Tainted Ideals is a Fan Fic for Fate/Stay Night, a 'what-if' story that follows the path Shirou would take if he was saved by forming a contract with Avenger and wishing upon the remains of the Holy Grail. He escapes the fire without ever meeting Kiritsugu and is adopted by Kotomine Kirei. We watch the result of Shirou being raised by an amoral priest and the King of Heroes; by the third chapter Shirou has summoned the Servant most suited to his heart, and soon after the Fifth Holy Grail War begins in earnest.Tainted Ideals can be found on Fanfiction.net, Beast's Lair, and Spacebattles. At the moment Fanfiction.net has the most up to date links to the newest chapters.
This work provides examples of:
Anti-Hero: Shirou is Type IV at best. If it weren't for his Morality Pets, he'd probably be a Type V.
In fact, in one of the alternate timelines Stormedge revealed, Shirou was either Type V or a full blown villain. He more or less won the war with Gilgamesh as his Servant, ate the world, and went off on intergalactic jaunts to consume more planets.
Kotomine Shirou, in addition to the usual ones of the FSN cast. Taking on Bazett and winning, despite his chest being caved in? Channeling Kirei as a executor? Hell yeah.
Big Eater: True to canon, Saber. Assassin, while also a Big Eater, can't hold a candle to her.
Body Horror: Shirou's familiars are absolutely horrifying. Rin has tried to get Shirou to stop disfiguring his creations. Now he just hides them from her.
Not to mention Shirou's own combat magecraft. He can turn his own arms into claws.
Broken Bird: Assassin's one. A very mean one, but she meets the criteria all the same.
Canon Foreigner: Constantin, Master of Caster. Since very little information is available about her canon master Stormedge more or less made him up.
Word Of God: "He is. Sorta. We don't actually know anything about Caster's canon Master (other than the fact he was an idiot), so I just thought of a reason he'd be less stupid and rolled with it."
Creepy Child: To the surprise of absolutely no one (except Rin), Kotomine Shirou.
It is likely thanks to her efforts that Shirou grew up to appear as normal as he does. In fact, Sakura doesn't think of Shirou as anything but a normal, mundane boy from her school.
Curb-Stomp Battle: Saber VS Constatin & Caster. Saber's insanely high magic resistance meant they never had a chance.
Curious as a Monkey: Shirou develops this thanks to his general emptiness - something has to fill it. It manifests in ways from wanting to check that plants really need sunlight to wanting to compete in a ruthless war between magi, and he approaches each in almost exactly the same way.
Cursed with Awesome: Taken quite literally with Angra Manyu possessing Shirou.
Disproportionate Retribution: Gilgamesh is displeased enough with stepping in cat mess that he seems to have personally gone and killed a number of cats in the area. Possibly with some of his ancient magical artifacts.
Dynamic Entry: Ilya via Excaliblast onto Shirou VS Bazett.
Evil Orphan: Shirou's more amoral than anything else, but he's so close to this trope that it practically doesn't matter. He just happens to have a Morality Pet in Rin while he grows up.
Face Palm: Shirou when Ilya said she won't kill him 'for now' in front of Assassin. And when Rider saw Shirou collapse in front of her and Assassin.
Familiar: Shirou's familiars are absolutely horrifying but extremely effective in combat.
Shirou when he first met Ilya, and when Assassin agreed to ally with Rin despite her obvious dislike towards Rin.
Foe Tossing Charge: Not a literal application of the trope, but Kiritsugu fighting across entire continents and decades of old enemies to get to Ilya definitely fits the spirit.
Garden of Evil: This is what protects Shirou's workshop. Rin nearly kills herself several times just trying to examine the plants when the two are eight years old.
Healing Factor: Shirou's got one, just like in canon. Unlike canon, he isn't letting a hitherto unknown ability to not die when killed go unstudied.
Hero Antagonist: Ilya's one of the most righteous and noble characters in the story, but that doesn't mean she's not Shirou's opponent and willing to kill him, if necessary.
Heroic Sociopath: Kotomine Shirou hides it so well that even he is not aware, but he really could not care less about the lives of anybody that isn't explicitly his friend.
Image Boards: Gilgamesh is part of one, his nickname is Kingofp0wners.
Imagine Spot: Rin has several about Kotomine Shirou, ranging from sweet to raunchy. She denies their existence.
It Amused Me: The entire Kotomine family, to an extent.
And Ilya.
Ilya: Whether it's falling onto a girl's chest as your love interest walks through the door, or making someone think you're going to kill them, it's all fun!
It Gets Easier: Apparently averted. Shirou has no trouble killing his first man, and in fact feels better after he does.
Jedi Truth: Gilgamesh when Shirou asked him about the Grail. Shirou's Genre Savvy enough to know he wasn't being told everything.
Killer Rabbit: Assassin can be shy, overwhelmingly cute, and have a soft side several miles wide for Shirou. And only Shirou. Everyone else, especially anything female, will taste swift and visceral death.
Bazett too, after summoning Cu Chulainn. She even faints!
Mad Scientist: Despite using magic, Shirou shades into this. His familiars are perhaps the best example of how ... interesting his ideas can get. Not that this makes them at all ineffective in battle.
Master Poisoner: Shirou demonstrates a very definite enthusiasm for all kinds of poisonous plants in his first meeting with Rin. Understandably, she's a little put off.
Morality Pet: Kotomine Shirou has several. Their names are Tohsaka Rin and Saegusa Yukika. Do not hurt them. There is a reason Shirou is classified as a Heroic Sociopath.
Coincidentally, Kotomine Shirou is Assassin-chan's morality pet. Hurting Shirou in any manner is also not a good idea.
Moral Myopia: Shirou has a bad case of this. Word Of God describes it as: Tell him that you'll kill ten thousand people if he doesn't say, give Rin a nasty cut on her cheek and he'll tell you to go right on ahead, whistling a jaunty tune as he goes.
Mundane Utility: The gigantic roses with thorns 'the size of small daggers' apparently discourage wandering cats from dirtying the church garden.
Not So Stoic: Constantin. He deals with his defeat...poorly.
Oblivious to Love: Despite Shirou being significantly more inquisitive and perceptive, enough to troll Rin for laughs on a regular basis, he seems to be completely oblivious to her attraction.
For that matter, he doesn't realize Assassin is going full-blown Yandere over him. Although Assassin is hiding this rather well.
Omake: Stormedge have written a few. Notably Gilgamesh playing Western RPGs, and another one where Kirei hilariously broke up Rin&Shirou's marriage ceremony to induce a Caren+Shirou end.
Pirate Girl: Rider, affectionately nicknamed Piratits. Arguably more of a Privateer. She's Sir Francis Drake.
Power Perversion Potential: Shirou, whose origin is 'Flesh'. Connect the dots. Word Of God states Shirou can indeed bring a woman to orgasm by only touching her.
Puppy-Dog Eyes: Ilya uses them to get her way with Saber. Who falls for it despite having known Ilya for years.
Roaring Rampage of Revenge: Whether Shirou had one is debatable. Mostly because his target died too quickly to really fit the spirit of the trope.
Shout Out: 'Gameplay and story segregation' - from one you wouldn't expect: Gilgamesh!
Take That: From Kotomine!Shirou to FSNcanon!Shirou: "What kind of idiot would simply accept that he had a mysterious healing ability, and then leave it to chance to determine if he ever found out its source or not?"
Rin fires one off towards her canon self. "She'd almost used a command seal, a power nearly on par with True Magic, over something as trivial as her Servant teasing her a little. On the actual day of summoning! What kind of idiot would do something like that?"
The Tease: Rider towards Rin. And we love her for it.
This Means War!: Caster and her Master's actions cause Yukika to be crippled. Upon learning this, and after a minor Heroic BSOD, Shirou pulls out all the stops to put Constantin's head on a plate.
Tsundere: Rin (well duh). However, her Rider seems to have a perverse pleasure in drawing out the tsun side. And Rin's 'dere' side is just plain adorable, eg when she's thinking about Shirou.
Undying Loyalty: Saber would give her life for Ilya without hesitation.