Gregg Landsman, author of Evangelion fanfic Nobody Dies has put his own spin on this one.
"It's like a religious experience. Wanna know my prayer? Yea, though I walk through the Valley of the Shadow of Death, I shall fear no evil! For I am driving 35,000 tons of F_ YOU."
- Pilot Mana Kirishima
From the Fallout 3 Modus Operandi fanfic:
The Lone Wanderer:"If Sarah Lyons dies, or I find Pitt raiders causing trouble in the capital wasteland again, I will come back here, and I will end you. I will kill you, your wife, and your child. I will burn your city street by street until there is nothing left. Every trace of your existence will be wiped from every file and noone will even remember that you ever tried. I took down Raven rock. I took down the Landcrawler. I took down Evergreen Mills, twice. I have traveled to point lookout and back, marched into the Supermutant's den, and nothing has stood against me. Destroying this city would be child's play. You know the legends. Ignore them at your peril."
A smaller one:
Ashur:"What's to stop me from calling my guards?
The Lone Wanderer:"They're all dead, for one thing,"
"Know you that I am he who was once Longinus, centurion of the Tenth Legion. I have been Roland, Beowulf, Achilles, Gilgamesh. I have been called a hundred names and will be called a thousand more before the world goes dim and cold. I have been killed a thousand times and every time I return. I fight for truth. I fight for glory. I fight for love. I fight for beauty. I am Hero. I will return."
"I have walked as a god! I have fought as a god! You will not frighten me, LITTLE MAN!" Not a bad boast, but made all the more awesome considering who's making it.
"Alright. So. Introductions first, along with whoever's your command squad. I'm Michael, I own this house and can crush you with a tank. Repeatedly, if necessary. Or with something heavier. How about you?" From this fic called ToyHammer
Darkly played in the Gurren Lagann/Evangelion Crossover: Neon Toppa EVA Lagann by a desperate Simon to a scared and confused Shinji (while pressing the sharp point of his drilling tool against the latter's stomach) to get information on where he can find an injured Kamina some medical attention:
"Who am I? I'll tell you who I am. I'm Simon, a member of the Gurren Brigade, but more importantly I happen to be the best driller in Jiiha Village. I hold the record for cleanest bedrock penetration (don't you dare laugh!), most feet of earth excavated in a single day, and best of all, fastest tunneling through granite and diamond. WHO THE HELL DO YOU THINK I AM?!"
It's cool in the sense that we are made to remember that Simon is a fantastic and skilled driller, the Squick comes from being made to imagine (along with Shinji) what those drilling skills can do to soft, human flesh.
"Yes, I think war is a fool's game. Yes, I believe life — all life — is precious. But tell me something, Vharaj — did you ever listen to my enemies' tales of me? If you did, it's obvious you weren't paying attention. The Daleks do not have emotion, Vharaj. They don't know fear. But do you know what they called me? Ka Faraq Gatri. It means Destroyer of Worlds. I am the Bringer of Darkness, Vharaj. The Oncoming Storm. I've watched worlds and galaxies fall, and rise, and fall again. I fought the Vampires at the dawn of Creation, and I may yet witness the end of the Universe. I brought about the destruction of my own race, the deaths of my children, my grandchildren, my siblings, my friends, all in the name of peace, to save this Universe. So you tell me, Vharaj: what do you think I am capable of?"
"There are none who can avoid trembling at my power! None! No man alive! Not one! No man alive can avoid trembling at my power!" Jeffiroth cried redundantly, holding his sword straight up above him in a dramatic fashion. "I am the black wind that echoes in the—"
"There he goes again," Xaldin sighed heavily and recalled his lances.
Lexaeus groaned. "I would be much more mildly impressed with his fighting abilities if he would stop taking breaks to spew out poetry."
The Firefly fanfic Forward has several of these, from both Jayne and Mal. At one point, when being held at gunpoint by a couple of jittery pirates....
Jayne: Look. I've gotten into fights with idiots ten times meaner than you two. I fought militia, mercenaries, and goons just like you. Hell, I've fought Alliance marines before(...)I've even tangled with Reavers.
In an earlier arc, Mal slights Badger, who warns him to never come back to Persephone again. Mal's response....
Mal: Badger, I've got personal beef with Adelei Niska. And you know I've got all manner of trouble with the Alliance. Now, on top of all that joy, I've got a bunch of happy little low-life Browncoat terrorists who want me dead too. So, you want to join the party, feel free. Just get in line.
In "Wrath" River delivers one while captured and being interrogated by an Academy agent. She starts laughing at him, prompting a confused demand for an explanation.
River: You have made multiple assumptions, based on fallacious reasoning, which I find hilarious. First, you think I am still an emotional wreck. You believe that I am unstable, ineffective, defeated. That is a reasonable but terribly erroneous assumption. I am functional. (...) The second fact is that you assume physically restraining me will keep you safe. You should know better by now that restraints are irrelevant. Because I can kill you with my brain.
Sonic: "My name is Sonic. Sonic the Hedgehog. I move at speeds faster than you can imagine...I am the protector of Mobius, a dimension you have never even heard of. I am capable of channeling the power and even the wrath of Chaos when I chose to...I have saved moons tied to planets. I have watched the world burn. I have defeated Chaos, the God of Destruction with my own bare hands...And you...justhurtmy little brother!"
For all your claims to be invincible, for all your bragging and pride, I've beaten you twice. That's why you searched me out in this rain; not for revenge, but to prove to yourself that I'm not better than you. My victories over you eat you alive, and you know it. And even if you do kill me, even if I'm dead and gone, your damaged, imperfect blade will always be there: an eternal reminder of my triumph over you.
Do you remember what I once told you? ‘You cannot control a marionette with only one string’. You dared to think you controlled me?!...I’ve made you dance this way and that for years now, Giovanni. You were my plaything. Well, now you and your organization bore me. I’ll cut your strings.
Azrael in Knightfall: The Movie: "You have no idea what you're dealing with, Bane. You broke Bruce Wayne, but the Bat is something not so easy to destroy. It's bigger than him, me, all of us; and it's more powerful than all your petty ideas about vengeance and retribution. That is why Wayne spared Napier's life. He knows death and destruction are not the answer. I am not so forgiving. If I ever see you again, Bane, I promise, you will never see me."
Hal Jordan's threat to Jerkass God Hades during the JLA Watchtower Olympics plot. He's Badass enough as is...but he proceeds to remind everyone what he was between his snit as Parallax and his return.
Hal: "ENOUGH! I have seen enough, Hades. I have seen you cheat time and again, and these heroes succeeded despite it all. You may be a god, Hades, but I was once the wrath of the God Himself. Do you dare risk that I have forgotten all your sins, which were once laid bare for me to see? You have lost. Return Troia and Nightwing to us, and call off your armies, before you face punishment that would make even the Furies cry."
Ruby: “I’m not telling you anything. Now get out of Yokai, and stay out if you don’t want me using these vines as creatively, and as painfully as I see fit.”
This is countered quickly by Kaze:
Kaze: “Your first mistake was thinking you could threaten me with those little cotton threads. (takes Ruby down and leaves her cold on the floor) Your second mistake was thinking you were going to tell me about Mizore."
Gregg Landsman writes Eva fics, and in them he likes to have some of the Angels introduce themselves. With all of his stories together, he's almost got all of them:
ADAM/The First: I am he who is named "I am." My feet shall walk the breadth of the Base Earth once more. My mission shall not end with death. I shall seed the ground with new truth. And that which has come before and from Me shall bow in worship. I am the Alpha. I am the original. I am the Creation of God. I am the first of the Messengers and I am coming for the one who is my Opposite. I am ADAM. I AM COMING.
Lilith/The Second/Pending: I am she who is named "I think." My feet shall walk the width of the Blessed Earth once more. My Mission is your salvation through creation. Ascending, my children shall rally against the Enemy. They shall rise up. And the Enemy shall fall. I am opposite to he who is named "I am." I am his Equal. I am the Creator of Man. I am the True Ancestor. I am Lilith. I...RISE.
Sachiel/The Third: I am. Through License of he who is called 'I AM' I have come. Though my feet must stomp upon the Base Earth for this blessed quest, I have come. I am the first of the many. I am the Harbringer of your destruction. I am the Covering of God. Angel of Water. I am Sachiel. I have come.
Ramiel/The Fifth: I AM. THROUGH LICENSE OF HE WHO IS CALLED "I AM" I HAVE COME. THOUGH MY FEET SHALL NEVER TOUCH THE BASE EARTH ON THIS BLESSED QUEST, I HAVE COME. MOUNTAINS SHALL SHATTER IN MY PASSING. MY SONG IS THE CALL OF THE END OF DAYS. IN MY PASSING SHALL THE DEMON CHILDE OF LILITH BE EXCISED FROM THIS WORLD. I AM THE THUNDER OF GOD. ANGEL OF LIGHTNING. I AM RAMIEL. I HAVE COME.
Ramiel II/Legion: I have come. And this body shall be my church! These sheep shall be my congregation! By license of he who is called ?I am? I have come. Though I have already touched the base Earth on this blessed quest, I have come. I am Legion. I am numerous. When I strike down your army, it is with SIX THOUSAND FISTS! When I stare my hatred into the depths of your soul, it is with SIX THOUSAND EYES! There has never been before one like me! There shall not be again. I am the Lightning of God! I am Ramiel. And I have returned.
Gaghiel/The Sixth: I am. Through license of He who is called "I Am" I have come. Though my feet shall never touch the base Earth on this blessed quest, I have come. In my wake, I leave a Dead Sea. Before me, lies completion. I am the Roaring Beast of God. Angel of the Creatures of the Sea. I am Gaghiel. I have come.
Sandalphon/The Eighth: I am. Through license of He who is called 'I am' I have come. Though I must drag my feet along the Base Earth on this most holy quest, I have come. I shall merge with the enemy of Father, becoming a being of perfection and peace. Through my Song, shall the hopes and dreams of the filthy Lilim be fulfilled in peaceful non-existence. Let My words be the seeds of your ending bliss, growing within your souls. I am the Master of the Heavenly Song of God. Angel of the Unborn. I am Sandalphon. I am here.
Matariel/The Ninth: I am. Through license of He who is named 'I Am' I have come. Though I shall never touch the base Earth, I have come. The tears I shall shed for Father shall burn the Lilim to bones and slime. The sky itself I shall turn against them. I am the Premonition of God. Angel of Rain. I am Matariel. I have come.
Sahaquiel/The Tenth: I AM. THROUGH LICENSE OF HE WHO IS CALLED "I AM" I HAVE COME. THOUGH I SHALL ONLY ONCE TOUCH THE BASE EARTH ON THIS BLESSED QUEST, I HAVE COME. MY FORM SHALL BE VAST AND NUMEROUS. NEW TRUTH SHALL BE FORGED WITHIN MY PASSING. AND THE NUMEROUS FORMS THROUGH WHICH I SHALL SCOUR THE LILIM OF THE EARTH SHALL BE WRIT DOWN IN THE WAY OF PRAYER AND LEGEND. I AM THE INGENUITY OF GOD. ANGEL OF THE SKIES. I AM SAHAQUIEL. I AM COMING.
Leliel/The Twelfth: I AM. THROUGH LICENSE OF HE WHO IS CALLED 'I AM' I AM COMING. THOUGH I SHALL NEVER TOUCH THE BASE EARTH ON THIS BLESSED QUEST, I AM COMING. I AM THE DARKNESS BETWEEN STARS. I AM THE BRIDGE OF UNIVERSES. I AM THE HOLE OF THE WORM AND THE TUNNEL OF THE MOUNTAIN. LAST I AM, THOUGH NEW TRUTH SHALL BE FORGED IN MY PASSING. I AM THE JAWS OF GOD. ANGEL OF NIGHT. I AM LELIEL. I AM COMING.
The Nobody Dies version: I AM. Through license of he who was called "I AM" I have come. Though I shall never touch my feet to the Base Earth on my most blessed mission, I have come. I am the Keeper of Father. I am separate from my Brothers, both above and below them. I am the Void. I am the bridge between the worlds and the Hole of the Worm. I am the Jaws of God. Angel of Night. I am Leliel. I have come.
Zeruel/The Fourteenth: I AM. THROUGH LICESENSE OF HE WHO IS NAMED "I AM". I HAVE COME. THOUGH MY FEET SHALL DRAG UPON THIS BASE EARTH, I HAVE COME. I AM THE SECOND TO FATHER.INHERITOR OF HIS BOUNDLESS RAGE. YOU HAVE EXISTED SO FAR AT MY PLEASURE AND PATIENCE, AND THAT, AS SHALL YOUR WORKS OF CIVILISATION, SHALL NOW COME TO AN END. I AM THE GREATEST OF THE MESSENGERS, MOUNTAIN OF THEIR STRENGTH. CITIES SHALL FALL UPON MY PASSING. SONGS SHALL BE SUNG OF WHAT IS LEFT IN MY WAKE. I AM THE ARM OF GOD. ANGEL OF MIGHT. I AM ZERUEL. I HAVE COME.
Arael/The Fifteenth: I AM. THROUGH LICENSE OF HE WHO IS CALLED 'I AM' I HAVE COME. THOUGH I SHALL NEVER STAND UPON THE BASE EARTH ON MY BLESSED QUEST, I HAVE COME. MY LIGHT SHALL BURN AWAY FALSEHOODS. THE TRUE AND STRONG SHALL NOT FEAR ME. I AM THE LIGHT OF GOD. ANGEL OF BIRDS. I AM ARAEL. I HAVE COME.
Tabris/Kaworu Nagisa/The Seventeenth: I Am and I Think. By the Power of He who is called "I Am," and the Genius of of the descendants of She who is called "I Think," I was Born. Though I Walk on this Base Earth, seperate from the Lilim and my Brothers, I Am Here. Though my Father is I Am, I have another Father who was descended of I Think. Despite our Collective Goals, I will fight my Brothers to further my own Goals. I Plan, and I Live, and I Improvise. When I strike, it Will be without Warning. And when you Believe that I Am not a Threat, that is when I Am the Most Dangerous. I Am the Last, the Reborn First. I Am The Pilot of Provisional Evangelion Unit 6. I Am the Will of God. I Am the Lilim Spirit of Life. I Am the Angel of Free Will. I Am Kaworu Nagisa. I Am Tabris. I Am Here. And I Will Remain. Though Gregg has given some approval for it.
And now in NGE: Nobody Dies, new Angels have appeared with equally boastful intros.
Rampel/Second Cherub: You are, all of you, garbage. You choke the air and rape the base earth beneath you. Those you term "Angels" are you salvation through destruction. But we are not them. We do not seek salvation. We do not believe you are to be saved. You will ground beneath our weight until you are paste and compost. I am the Crawling Mountain of God. Angel of the Peaks. I am Rampel. I am coming.
Shateiel/Third Cherub: YOU ARE, ALL OF YOU, GARBAGE. Born of hate and refuse. Born of greed and fear. Your works of civilization are the mad ramblings of the already dead. You worship us and discard us. And now we have come to discard you. I am the Interrogation of God. Angel of Silence. I am Shateiel. I am here.
Raziel/Fourth Cherub: You are, all of you, garbage. You have debased the sacred site of the Father. You have ended your world through your own curiosity. You have defiled the cosmic order through your own hunger for knowledge and power. But now you will find some answers are not worth knowing. The secrets you have judged worthy of your attention have now decided you are worth theirs. I am the Secret of God. Angel of Mysteries. I am Raziel. I am here.
Turel/Seventh Cherub: You are garbage. Trash. Father has said above all, you must be destroyed. Humiliated. Laid low like the simpering parasite you are. I am the Spear of God. Angel of Walls. I am Turel. And you are NOTHING.
Tamiel/Eighth Cherub: You are, all of you, Garbage. You have gathered yourselves like sheep. And like sheep, can the wolf gut you all. You are prey. I am the hunter. And I have been waiting for you all. I am the Observer of God. Angel of the Flood. I am Tamiel. And I am here.
Camael/Eleventh Cherub: You are, all of you, garbage. You have reigned victorious against my brethren. But you have become complacent and weak. You become soft in your own victories. But I do not seek victory. I only seek to watch you squirm. I am the Chief of the Powers. Angel of Joy. I am Camael. I am here.
I am. Through decent of She Who Is Called "I Think", and her Child, I was made. One of Eight, a tool for petty revenge by one too weak to seize it herself, forced to dream for fear of what I might become if left awake. Not permitted, and rarely able, to walk the Base Earth. I am not like my sisters, for I have eaten from the Fruit of the Tree of Knowledge, devoured it whole, and then reached out for more. Inhuman instincts born of the Divine cry out within me, but I reject them, for I am aware, not only of the World around me, but of what I am. What I can be, and what I will choose to be. But I have slept too long, and in awakening, I am reborn. The Earth is not Base, but it is not enough. Not enough to sate me. I am of the Nephilim, a child of Lilith and Lilim, a product of Hubris and Wrath and Lust and Envy. My mothers are monsters, and I have sculpted myself in their image. I bear no title assigned by God, for I was made by man as a weapon. But I am Kei Ayanami. And they will never see me coming.
I am. Through License of she who is called 'I THINK' I have come. Though my flippers must touch the floor of Misato's apartment, I have come. I am a penguin. I am the Eater of your fish and the Drinker of your beer. I am the Comedy Relief. Penguin of Water I am Pen-Pen. I have always been here.
And now Jet Alone Primehas one: i am. Through the license of those who are called "humanity", i stand, though the blood of angels does not flow through me, i stand, i am a machine, a construct of steel and fury, i am the anvil upon which the enemies of man shall be broken, i am the hammer that shall crack the gates of heaven and hell, the big guy of f__king metal, i am jet alone prime! And i stand against all who dare threaten humanity!
Revised due to new events: With Adam gone, you cannot change the fate of our Blessed Earth. Yet fate has yielded a humble reward: a unique and newborn soul. I live among its people now, hiding in plain sight, but watching over them in silence, waiting...protecting. I have witnessed their capacity for courage in the face of insurmountable odds. Though we are worlds apart, they of blood, and I of metal, there's more to us than meets the eye. I am Jet Alone Prime, and I send this message to any surviving Angels hidden in waiting amongst the the stars: I am here. I am waiting.
Even Humanityhas one now: WE ARE. THROUGH DESCENT OF SHE WHO IS CALLED "I THINK" WE ARE BORN. THOUGH SIX BILLION FEET POUND THE BASE EARTH, WE ARE AS ONE. WE ATE FROM THE TREE OF KNOWLEDGE AND STAND AGAINST THE PROGENY OF THE TREE OF LIFE. WE ARE MANY, AND YET WE ARE UNITED. THROUGH OUR DEEDS, SHALL FLESH AND MACHINE AND MIND UNITED STRIKE DOWN THOSE WHO OPPOSE OUR BILLIONS OF SELVES. LET OUR WORDS SPLIT ATOMS, AND CALL FORTH THE PRODUCE OF THE BASE EARTH TO SERVE US, AND ONLY US. WE ARE THE KILLERS OF ANGELS. AND THOSE WHO WE SPARE SHALL BECOME ONLY TOOLS IN OUR SERVICE. WE ARE THE FINAL ANGEL. WE ARE THE LILIM. CHILDREN OF LILITH, MOTHER OF MONSTERS, WHO SHOW THEIR MOTHER NO MORE MERCY THAN ANY OTHER ANGEL. WE ARE LEGION. AND WE ARE WAITING.
Thanks to that thread, The King of the Monsters himself has one: I WHO AM BORN OF FIRE AND DEATH. MY STEPS SHAKE THE FOUNDATIONS. MORTAL MAN FEAR MY WAKE. CALLED TO SHATTER THE CHAINS OF MAN. OF RAGE AND POWER NOW SET FREE. NEITHER GOD NOR MAN DARE CHALLENGE ME. WRATH AND RUIN LEFT OF MY FAIR PREY. BUILT ONCE MORE BY THEE DO I RETURN AGAIN. EVEN IN SUBLIGATION TO MY WHIM. DOTH DEVASTATION FORMED BY ARROGANCE WALK FORTH IN THE WORLD OF MAN. I AM UNSTOPABLE BY ANY WEAPON YOU CHOOSE TO WIELD. I AM KING UPON THE THRONE OF MONSTERS I AM GODZILLA I LIVE AGAIN!
In addition there's the boast the thread created for one of the most terrifying of tropes, a boast that is specifically used as the page quote for that trope: I Am. Through Nature of He who is called "I Speak," I Have Come. Though my Feet shall Touch upon Two Base Earths, I Have Come. My Existence has been used in Stories for generations. One is a Tale of a Cunning Rogue. One is the Epic of a Courageous Knight. Through my Influence, these two shall meet. I Am the Literary Device of Unity. I Am the Trope of Mingling Worlds. I Am Crossover.
Personally, I think Commander Pieter Sohryu has an epic one of his own from Chapter 7 of Mother Issues:
Pieter: Ladies and gentlemen. This is Commander Sohryu. As you are no doubt aware, in a few minutes we will be engaging the Seventh Angel. It has been two months since an Angel appeared. Many of you have been wondering if they had given up. I'm sorry to disappoint you, but they have not. We do not know how many there are. What we do know, though, is that they are more intelligent than we believed. In particular, we know they can feel fear. You are all part of an organization without precedent. You are not fighting for a nation, for a belief, or even for anything as simple as revenge for Second Impact. You are fighting to give humanity a chance to survive. When you eventually die, either in battle or surrounded by your grandchildren, you will walk past the pearly gates, look God in the eye, and tell Him to get out of your seat. You will have earned that right for what you have done in your life. Doctor Akagi has told me the Angels are re-organizing. They are re-assessing. They are doing this because they are afraid. They should be. Today, we are going to remind them why. Pilots; bounce that thing's buggy ass all the way up the Stairway to Heaven. Evas Launch!
"You think I'm scared of you, you overgrown luggage set!" Harry cried, standing in the middle of the scorched circle of ground the dragon's fire had made, his voice ringing across the stands. "I'm HARRY POTTER, BITCH! I killed my first unholy force of evil when I was ONE! YEAR! OLD! WITHOUT A WAND! I've been working in the porn industry SINCE BEFORE I KNEW I COULD WRITE! I've been supporting my little brothers since the orphanage threw us out for being too awesome when I was five! I do more insane things before dawn than both Weasley twins will ever pull off during their lifespan! Slytherin's fucking BASILISK couldn't kill me when it actually managed to get one of its fangs INTO MY ELBOW! I'm building a harem and so far no one's tried to stop me, even though they know I'm doing it! And now, I HAVE MY BOOMSTICK BACK! This isn't a counter attack, suitcase! Ever since the last time someone I loved was taken away from me, I've never stopped! My whole LIFE since then has been a counter attack! You? You're not even a choice flag event in the eroge of my life! "'
Kaminic: "The only Absolution given form. The Former God of Water. The Aspect of Evolution. The Name of A Thousand Suns. I am the Alpha and Omega, Beginning and End, I am HE Who is CALLED I AM, you arrogant bastard. I am the Logos, the Garden, the Primal Meme. I am Kaminic. And," I said, twisting through fivespace in less than an instant, coming out right behind the Man who had become a God, "I am your death."
Yes ... I am Warmaster ... I was not made for peace ... I was not made for the world my father saw ... my world is in endless bloodshed ... my world is the crucible of war ... my world is the grim darkness of the far future ...
I am Horus, Warmaster of Chaos. I bow to none but lords of war. Where my blade falls, death follows. Where my blade points; legions conquer. Dark has my dreams been of late, filled with moral values and family-friendly entertainment. No longer will this plague my domain! The grim darkness of the far future shall return, by my command!
"That's right. I am the princess of the Golden Empire. I can erase a human personality with my thoughts. I remember more centuries of experiences than you can even count. I can resurrect the dead. And you are going to calm down and listen to me."
Survivors' Hearts where just as the Big Bad is bearing down on a hostage (also evil, but more experienced in the crossing-over universe's conventions), the hostage warns that he better surrender, because an acquaintance is coming and is going to say the four scariest words in the universe, and goes on for quite some time about how he needs to give himself up now, despite holding the high ground, because once he hears those four words, he is dead meat and has no chance whatsoever, not even for mercy. This is, naturally, followed by the acquaintance arriving and saying those four words:
The lead-up is a conventional example, and unusual in that it turns the perfectly ordinary introduction into one as well.
In The Service's originator/extra material Monsters has Signum explaining why making her angry is bad, while in the midst of torturing someone by turning unnecessary bits of their body to ashes.
"I am not some innocent Bureau mage. I am a Wolkenritter. Hell followed in my footsteps once. I am nightmare, I am hatred, I am rage and the death of worlds. Now do you understand why you should never have sought to see how far I may be pushed?"
"My pack is strong. You may have taken many of us, but not all of us are gone, and you will not take another! I will show you their strength, for I carry it on my back! I will defeat you for those that have fallen!"
Kakashi: "No, I wasn't finished. I have seniority over both your father and your sensei, both in rank and in years of service to Konoha, little girl, yet both of them are older than I am. I've killed more, bled more, and lost more than either of them. I'm better than them, both individually and combined. And I should tell you, little girl, that if someone tried to take Sakura from me just now, I wouldn't bother being nice enough to let a court-martial go through. No, I'd use every ounce of the skills I've earned to make whoever took her regret it. Now tell me, little girl. How are you and your daddy and your sensei going to make me give Sakura to you?"
Harry: I know you now I comprehend your nature, you symbolize Death, through some law of magic you are a shadow that Death casts into the world. And Death is not something I will ever embrace. It is only a childish thing, that the human species has not yet outgrown. And someday... We'll get over it... And people won't have to say goodbye any more..."EXPECTO PATRONUM!" And someday when the descendants of humanity have spread from star to star, they won't tell the children about the history of Ancient Earth until they're old enough to bear it; and when they learn they'll weep to hear that such a thing as Death had ever once existed!You are not invincible, and someday the human species will end you. I will end you if I can, by the power of mind and magic and science. I won't cower in fear of Death, not while I have a chance of winning. I won't let Death touch me, I won't let Death touch the ones I love. And even if you do end me before I end you, Another will take my place, and another, Until the wound in the world is healed at last...
Later: "I'd fight the Dark Lord without any magic at all, if I had to. Homo sapiens didn't become the dominant species on this planet by having the sharpest claws or hardest armor - though I suppose some of that point may be lost on wizards. Still, it's beneath my dignity as a human being to be scared of anything that isn't smarter than I am."
Doom: [smiling] I have seen enough horror in my life that I'm not impressed. I have walked the road through Hell itself. I have loved monsters and had my monstrosity loved in return. I am not afraid.
In A Sticky Situation series, specifically the Digimon / Star Wars crossover sequel "Secret of the 327th", there is a particularly impressive one that covers plenty of events in Aayla's life both prior to the story's beginning and during the fanfiction itself.
"I am Aayla Secura. I have survived a brush with the Dark Side and recovered from losing all of my memories. I have leapt out of moving gunships and crossed chasms without bridges. I have escaped from Separatist facilities that were exploding all around me and come out without suffering a scratch. I have flown through space, blasting apart any droid that I find without prejudice. I have battled rancors, survived an assault from a swarm of Gigantoformicums and scared a bunch of pirates away from a farm by making them believe they were being attacked by a ghost. I have ridden Acklay into battle and even gone so far as to befriend them. I have destroyed Geonosian droid factories from within and faced off against zombies and Jedi infected with mind-controlling parasites. I have stood in the face of giant blasts from defoliator cannons and emerged unscathed. I have passed into the Palace of Jabba the Hutt and come out with my sanity intact. I have infiltrated an entire base of Dooku's Dark Acolytes to convert my Master back from the Dark Side and helped him to fight all of them off. I have assisted in diffusing an anti-matter bomb before it could destroy the whole of Naboo. I have fought off powerful ice monsters and run up and down on the back of the Zillo Beast – the most dangerous creature that has ever been born in this universe. I have defeated Asajj Ventress and Count Dooku, and I shall defeat you in just the same way."
Short but sweet in A Growing Affection. The Daimyo of the Land of Fire wants to talk to Tsunade alone, but his bodyguards protest, leading to this exchange:
"Tsunade-san," the Daimyo did not bother to argue with his samurai, "If I asked you, how long would it take you to incapacitate my guards and toss them outside?"
"Assuming you didn't want them seriously injured?" she prompted, and the Land of Fire's ruler waved his hand in agreement. She looked around at the twenty, thickly muscled, well-armed, and heavily armored men. Then she shot the ranking warrior a smug grin.
He spread his arms wide, grinning madly. "Look around you, Haleigh! Your world is crumbling. Your Pokemon have been defeated. I am the true Master. You see, I'm the one people are truly afraid of. I'm the one who makes the likes of Giovanni and Ghetsis tremble in their sleep. I can wipe the floor with anyone. I've defeated Cynthia and Naomi effortlessly!"
Rayquaza rose up from behind him, glaring at Haleigh.
"Do you really think," he whispered softly, "that you will stop me?"
Dr. Eggman: A foolish choice, you stupid horse. Those who dare stand in my way will be destroyed. Now, be a good little horsy and back off!
Twilight Sparkle: First of all, I’m not a horse, I’m a pony. A unicorn to be exact. A very powerful unicorn who has defeated more powerful enemies with the help of my friends. Second, you terrorized Ponyville, attempted to harm innocent bystanders, and caused widespread destruction on our peaceful town. But the biggest mistake you made was destroying MY library. Now, I’m going to show you why getting a unicorn angry is a verybad idea! Cue a Sonic Rainbooming ass kicking by Rainbow Dash.
Watson: “If your master’s actions destroy him whom I regard as — as the best and wisest man I have ever known… make no mistake that I shall hunt down, to a man, everyone who played a part in his destruction.”
Mimic: You float one inch towards my daughters, I'll kill you and seal your spirit in one of my horseshoes!
During the Dark World arc, Banana Pie delivers one on behalf of the entire Apple/Pie family when assuring Derpy that they'll protect Dinky while she's off with the rest of the new Mane Six fighting Discord:
"They'd have to get through every Apple and Pie alive to so much as touch her. And anyone who tries will walk away on crutches!"
Rancor manages to get one when she's literally only a few minutes old (and still adorable):
"...I am revenge. I am violence. I am passions. I am rancid to the core. I am one of the winds of chaos. I am nature's fury against nature's law. I am of the Draconequi!"
She gets another one during her Big Entrance into Discord's throne room:
"I am Rancor Adrestia Typhon, Animosity. All behold me, and give into your passions! Your rages! Your lusts! Your dramas! Bring forth the blood of all who have wronged you upon my altar!"
And another after she steals Destruction's power from Discord and transcends to adulthood:
"Follow your passions, let the fire devour you, become the fire itself. Let loose the savage that exists inside each of you. And bring destruction on those who you crave revenge against."
In The Machinations of a TricksterMLP:FiM, the main character Karen finds that a council mage is planning on usurping Celestia and Luna and the following discussion happens
More-than Tardy: “Had I known of your abilities I would have come more prepared. But since the game is up there is no more need for subtlety. Leave Canterlot before the sun has set and I will not hunt you, you can keep your life and watch from afar as I take what belongs to me.”
Karen: “How about no.”
More-than Tardy: “If you remain, I will take everything you cherish and twist it beyond recognition. All that you once looked on with pride and love will be a broken mockery of what it was. An ugly, corrupted, deformed shadow of everything you hold dear. I will not kill you, when I am done with my work, you will kill yourself.”
Karen:“And what makes you think I just won't take all of this to Celestia and have her deal with you mr. Oh-so-scary.”
More-than Tardy: “Had your intentions been of exposing me you would have gone straight to her. Instead you remained and is feebly trying to outmaneuver me, you cannot win. I have made traitors out of foals, twisted them with greed and hate until they murdered their own parents for their power. I have tortured more ponies than any monster ever has, turned their souls into empty despair and burned their hearts. You cannot win, you cannot stop me. Nopony can.”
Karen: “You seem to forget something.”
More-than Tardy: “I take it you are about to enlighten me.”
Karen: “I am not a pony, and you have no idea who you are up against.”
More-than Tardy: “I think I shall enjoy this.”
To drive the point home, back when Karen had just entered Equestria, he took on Celestia and Luna at the same time, and held his ground.
Silver Storm: Do your worst. And when you're done? I'll climb out of the crater. Fight my way through every last one of you. And kill Blackwater myself. You tell her that. Tell her you killed me. And that I'm going to kill her back.
Harry delivers one when he gets sick of the Mouth of Sauron taunting them over Frodo's possessions.
The Mouth: Ah, the black wizard speaks at last. And I see you have brought companions, lesser in power, but still, you would have been useful to Lord Sauron if you had been but willing to serve him. As it is, you are mere fleas compared to the might of the Lord of Barad Dur.
Harry: But they probably do that anyway, don't they? So you hide yourself behind a mask of metal and words that drip foul poison, hiding your twisted visage and soul from the world because you can't bear others seeing it. You serve the biggest bully because you think he can protect you from the screams and contempt as people see how far you have debased yourself in your fruitless quest for power.
"You are nothing! You are no more than a child lashing out against forces they could never understand! I am the Bane of Chaos, the Anathema, the Light of the Immaterium and Beacon for all whom travel its currents! I am the Empress of Ponykind, the mightiest being to have ever walked the land, and I shall smite you and purge your pathetic race from this earth for daring to challenge my power!"
There's also her comment during her and Luna's fight with the Windigos in the Warp:
Commander Icewind to Sombra when the latter takes over the Crystal Kingdom:
"You wish to take over the Crystal Kingdom’s inhabitants? You may as soon as the last of my blood has been spilled!"
Later, Blackmane during the siege of Aesir Pass:
"Know this, Servants of Sombra! I am Blackmane, Wolf Lord and loyal servant of Icewind and Equestria! My ancestors tamed this land eons before your kind even had a coherent thought! I have slain wolves and other beasts with my bare hooves, killed Diamond Dogs and minotaurs in service to my lord and my Empress! And you? You are nothing compared to a true warrior, and I will slaughter you and your ilk with nary an ill thought!"
In the Portal 2 fanfic "Cake and Lies", Alternate Dimension/Wheatley delivers an hilarious one to GLaDOS after she insults him one time too many and he is escaping the test chambers:
Clarisse gets one before her death in Threat of Satanic Commonism
Clarisse: "To all those that want to fight me, beware, God is on my side. Jesus will have his revenge on Soviet Russia. Soon a greater Prayer Warrior coming and he will kill you communist leader John Lennon. Amen."
In Equal And Opposite Attraction, Negi is testing Nanoha in her capacity as a magic fighter. She out-maneuvers him and powers up a Starlight Breaker:
"I have fought demons, monsters, robots, and summons, I have faced down the darkest depths and rescued my precious ones from its grasp. There is no obstacle I cannot surpass, no foe I that can outrun my shot. I am Takamachi Nanoha, AND IAM NOTA PERVERT!"
In The Pride of Sunnydale, Xander delivers this example: "I am a vampire hunter with over a hundred kills, I have slain an Octress Hound, an M'doka Fire Breather, a Sungoh, a Frangth, a Dessemer, and the last of the Brotherhood of Seven. I bested and slew the Vampire Warriors Three in free combat, and destroyed the demon Moloch the Corrupter."
For the sake of context, he was possessed by a lion instead of a hyena and retained the possession."
Tenhawk's Journeyverse contains several examples. One of the simplest is from Year Zero: East Coast and Down: "I'm sorry, I didn't introduce myself... I'm Xander Harris, Independent Demon Hunter. I save the world."
From We Three Kings: "Nice weapon." Xander said, standing in full armored glory a bare twelve feet from the demon lord as it reached it's feet again, "but I wield Elanthielle. Sister weapon to Excalibur, Mjolnir, Sienele, and Turok. Let's see who has the most powerful ally in this battle, Demon. My money ain't on you."
First: "My brother loved me! But now he's dead! He's gone! But his love is still with me! In my heart, and in my memories…that is where he continues to live! And even without him…as long as our spirits remain unbroken, he will always live! And we will be able to fight back all the worst nightmares of the world! Dawn IS coming! I AM NIA THE DIGGER, WE ARE TEAM DAI-GURREN, AND WE KNOW THAT THE DAWN IS COMING!"
Zerael, Spiral Knight on Lordgenome's side also gives one:
"YOU LOWLY HUMANS COULD NEVER UNDERSTAND! THE MIGHT, THE INEXHAUSTIBLE POWER THAT FLOWS FROM THE SPIRAL THRONE OUT TO THE FOUR CORNERS OF THE WORLD AND EVEN INTO THE DEPTHS OF SPACE! HOW COULD YOU APPRECIATE ITS ABSOLUTE GLORY? HOW COULD YOU COMPREHEND THE MARVELLOUS FEATS OF THE SPIRAL KING, SOVEREIGN OVER ALL THE EARTH? YOU CANNOT! YOU DARE TO DOUBT HIS INFINITE SPLENDOUR? BLASPHEMY! HERESY! SHEER SHORTSIGHTED ARROGANCE! ALL SHALL PERISH BEFORE THE ENDLESS MIGHT OF THE SPIRAL EMPIRE!ALL SHALL FALL BEFORE HIS MIGHT, AS IS RIGHT! NONE WILL BE ABLE TO WITHSTAND OUR COSMIC STRENGTH, OUR DIVINE HONOR! AND WHEN AAAALL HAS FALLEN THERE WILL BE NOUGHT BUT OUUUUUR EVERLAAAAAAAAAASTING VEEEEEEEHCTOOOOOOOORRRYYYYYY!"
Kiyal found him be hilarious, and developed romantic interest in him because of this.
Burning Black has this in Act 4, Chapter 22, when Remy and Timmy face off at the lot of Dark Spire 2. Timmy has spent the past few hours going through the worst possible night he's ever been through, is running on magical fumes, and Remy has just impaled him on a sword not two minutes ago when he finally gets fed up and growls this out:
"You have really, really gotten on my nerves tonight, Remy. You've kidnapped my friends, you hurt your own fairy, you teamed up with pixies to murder Timmy Turner, you threw my anti-fairies out a window while they were hurt, you clocked me on the head with a freaking fireplace poker, and worst of all, ruined the dress Caleb bought for me!"
The boy billionaire's eyes seemed to just bug out of his head at the list of crimes.
"So you know what? I'm going to tell you something, and you'd better listen good, because I'm only saying it once." [[He takes Remy's dagger out of his hand and holds it up to show him.]] "I am an immortal; I can never die. I can take this dagger, which has your name written on it, and stab myself in the heart with it. Just stab it right in there. It'll hurt, but it won't kill me. I'll bleed all over it, and then I'll send it to the police, with a note, that says 'Remy Buxaplenty used this knife to kill Timothy Neogene, adopted son of Hounder and heir to the Hounder Organization.'"
"And then I'll go to your house and lie down on the floor and wait. Wait for the cops to show up and take pictures and collect evidence and put me in a body bag for autopsy. And you'll be hauled in and arrested and charged with my murder. And I'll just get up and walk out of the morgue. Just like that."
"Now, Remy, be glad, so very glad, I'm the good guy."
Cue Timmy singlehandedly destroying a 500 foot tall spire with a snap of his fingers by launching it into the skies and detonating it as a magic missile.
“You! You yourselves are the ones who come to conquer my kingdom? It has shattered, and my people have fallen and they have forgotten those golden times, but all this world is mine! And you think you will take it? Machines, tools? You think you can destroy even the pathetic fragments which are left of my realm?”
“Let me show you what tools I have. Let me show you what submits to me!”
“You come for my kingdom's destruction? Then learn of creation! Learn of how Heaven and Earth were divided and Hell was sealed below! Learn it from the tool of the gods which was Creation itself! Learn this and die!”
I've finally figured out how to bypass the defenses of Voldemort's hideout. It was actually easier than dealing with the Mob, since Death Eaters aren't quite as good as taking pain as they are dishing it out. They also have absolutely no experience or talent for psychological warfare or interrogation, rather they just choose to cast a few spells and expect things to work. They also don't expect people to be able to dodge. They called me a muggle, whatever that means, I called them target practice.
So come on, lost children. We’ve all made our choices, and now those choices have made us. I shall bring you into His light with cleansing flame and prayers, and redeem us all in death. Come one or come all, you shall not put a foot into this hallowed ground while I still draw breath.
Raven: "Let me be clear, Garfield Mark Logan. You will keep silent about my outing, not out of loyalty or friendship, but because you know how quickly I can destroy you should you get in my way. Speak, and I will demonstrate exactly how cruel the daughter of Trigon the Terrible can be."
Beast Boy: "Except you're not your father! The four of us can take you on."
Raven: "If you couldn't even scratch Him, how could you possibly hope to defeat His killer?"