Alternate History Wank: To a degree; the Byzantine Empire expands considerably under Skantarios' guidance, even reaching places it never conquered in real life. And that's not getting to what his family and allies try to do after his death.
Anticlimax Boss: In-Universe. The final confrontation between Skantarios, representing the Orthodox Church and the Pope is... underwhelming, to say the least.
Combat Pragmatist: Specifically targeting, ambushing, and ruthlessly executing enemy generals, isolating them from their armies and cutting them down, in order to break the enemy's morale.
Kill It with Fire: Burning entire units of enemy soldiers to a crisp with his flamethrowers/siege weaponry, and showing no remorse for it, to counterbalance his constant disadvantage in numbers.
Leave No Survivors: Executing pretty much all of the prisoners he captures to ensure that he doesn't fight the same units twice. On the rare occasions he doesn't do this, it's usually because he's using them as bait for another enemy force. This comes as much from him as his enemies, who refuse to pay the ransom nine times out of ten.
I Shall Taunt You: Taunting enemy soldiers, particularly Muslims, to get them to sally out and attack. At one point he claims himself the father of the next generation of the city. When that doesn't work, he presents what he claims to be the ashes of the Prophet to a Turkish garrison, and puts it inside a pig's corpse. The Turks go berserk.
Trying to Catch Me Fighting Dirty: Using his spies to infiltrate every city in his path and open the gates to his armies, mercilessly executing the garrisons within, in order to reduce casualties among his forces.
Shoot the Dog: Exterminating every Muslim who crosses his path, tearing down the Dome of the Rock, torching the Kaa'ba (and the faithful Muslims still inside with it), and burying the caves where Muhammad received his revelations, in order to make sure that Islam never threatens the Byzantine Restored Roman Empire again.
We Have Reserves: Mercenary units are deliberately used to draw out enemy soldiers, take hits from enemy arrows, block cavalry charges, and to wear down enemy numbers prior to elephant assaults. Skantarios even worries about this somewhat, as overreliance on mercenaries is one of the reasons that the original roman Empire failed in the first place.
Author Avatar: Inverted. It is more likely that the author's user ID is named after the character than vice versa.
Awesome Moment of Crowning: Skantarios gets one when his father is killed by an assassin. A rather inept one at that, for he gets hunted down and murdered by his network of (usually) insanely effective spies almost immediately thereafter.
Badass / Determinator: Both meta- and in-universe example - Skantarios the character and Skantarios the author. Look, if half the world hates you, your army is starving and close to desertion, and your only major city is besieged from the get-go, you have to be both of the above to even survive, let alone turn the table. The author gets plus-points for being the one who actually plays in that impossible setting.
Badass Army: Skantarios can be proud to say he owns the world's leading Badass Army about ten turns in, and he eventually gets several of these. The Imperial Army is still the best, as they demonstrate repeatedly during his genocidal campaign against Islam, but the campaign against the Ottomans and Rus show that his subordinates have some utterly invincible troopers as well.
Badass Grandpa: Skantarios continues kicking ass well into his sixties. By that point, he's a literal grandpa to boot.
His story started in 1450 AD, this means he lived to 113 and still rode his horse the last day of his life.
Bunny-Ears Lawyer: Tiverios ek Konstaninoupoleos, the Bishop of Thessalonica, has odd habits, but he does his job very well.
Cool Versus Awesome: Several ten star generals including the best the Mongols have to offer, giants of the late medieval world themselves, crumble in the face of the even more formidable Skantarios and his generals.
Fail O'Suckyname: Skantarios says that "ibn Mahbub" (the name of a Moorish general) is "more of a joke than a name".
Famous Last Words: A soldier of the Jihad carved a signpost on the road to Constantinople when the Muslim armies are losing badly. When Skantarios discovered it, he asked a translator what it meant. Turned out that the poor soldier wrote on the signpost: "The place where Muslims go to die". Sniff, sniff...
Femme Fatale: Arguably Anna Laskaris. Although she is far, far more patriotic than your average Femme Fatale has any right to be.
Freudian Excuse: Skantarios' hatred of Muslims is catalyzed by the murder of his father by an Egyptian assassin.
Heir Club for Men: Skantarios is continually frustrated by his inability to produce a son.
He Who Fights Monsters/ Pyrrhic Villainy: Hundreds of thousands of dead enemies, dozens of massacres and sackings, and years and years of warfare reduce Skantarios to a man filled with nothing but hate, even for himself.
Idiot Ball: A Doge of Venice strolling into the Balkans hundreds of miles from Venice with only a small bodyguard to be fought and captured may be an Acceptable Break From Reality, but his successor doing exactly the same stupid thing one year afterwards is too much.
Invincible Hero: Skantarios never loses on the battlefield, despite frequently unfriendly odds. At the end of the first Jihad, Skantarios tallies up the thousands of fallen Jihad warriors in the burial pit outside the city. Recalling the Islamic tradition that every fallen Jihadi receives 72 virgins upon entering heaven, he calculates that Allah will need to find over a million virgins to satisfy that fallen warriors' needs.
In fact, Skantarios' job as Emperor dooms his chances of a normal, happy marriage. Near the end of the story, he admits to his wife Maria that his constant absence due to his military campaigns made him a terrible husband; she agrees, but recognizes that it was necessary for the survival of the Empire, even if she was upset that she could never have a son.
Last Stand: So, so subverted with multiple successful defenses of Constantinople. By the time the Jihad rolls along, the city of Constantinople has survived so many along those lines that it is rather expected.
Leeroy Jenkins: Many battles are won because of the enemy general charging headlong without waiting for the rest of his troops. Many other units are eliminated piecemeal in this fashion.
Modest Royalty: Deconstructed. Due to spending most of his life on campaign, Skantarios feels more at home in Spartan surroundings, even preferring a rough cot to a comfortable bed. Unfortunately, this makes it very difficult for him to transition to being a "stay at home" emperor.
Not Me This Time: Skantarios first suspects the Byzantine nobility in is Father's assassination (which makes sense, considering they'd been involved in many intrigues throughout Byzantine history), but he realizes they're blameless when the Egyptians start celebrating their assassin's success.
Old Soldier: Skantarios himself becomes this over time as more and more of his contemporaries start dying around him.
The Pope: Several popes take a role throughout the story.
Reality Ensues: In his report, Skantarios discusses that he'd like to say that his duel with Pope Nicolaus IV was the stuff of legends... but his opponent was nearly eighty, had never handled a sword before, and could barely ride a horse, so he barely put up a fight.
Also, during Skantarios's raid into the Egyptian heartland, he doesn't know what's going on in the rest of the world, unlike the games the series is based on. Of course, you'd expect that from going behind enemy lines in the days before modern communication.
Theodoros matches his son in the field of oratory, as he demonstrates in this speech just before the first of many sieges of Constantinople:
The emperor strode out before them and spoke in a clear, calm voice:
“You have all been judged and sentenced to death.”
A murmur of incredulity rose up from the ranks. Numerous whispers could be heard from the ranks: “Why?!?” “For what?” Was it a joke? Had they not heard him correctly?
Theodoros continued, thundering now above the murmurs: “You may be asking yourself for what crime you are accused and then sentenced. Your ‘crime’ is being born a man and being conscripted into this army. Your crime is that you belong to a nation at war. There is no judge, procedure, or appeal to this sentence. This sentence is final."
“There is hope, however. You can gain clemency by defeating your foe. Pass your sentence onto the enemy. Buy your life by taking his…for yours is already forfeit. By crushing him and driving him back to the steppes that spawned him. For, if you fail, you are dead. If my own men don’t kill you, the enemy surely will. If you fail, you not only condemn yourself to death, but your wives, your children, and all that you hold dear. Death, enslavement, and ruin are all that await you should you falter or fail today. The enemy will have no mercy and neither will we. Better to die here than to run."
"Make no mistake, there are no other alternatives. Win today, or die today. It’s an easy choice. You are already dead. Today, tomorrow, ten years from now; we all wind up in the same place. Buy your life today and that of your family. "
- page 1: "War with the Turks Begins" - June, 1455 AD
Parodied in the Third Battle of Ankara. By this point, we're accustomed to Skantarios' eloquent speeches. He goes to the men to deliver a speech to get them in the right frame of mind. It consists solely of "Kill them all!"
Took a Level in Badass: Some of the generals and Skantarios' sons prove themselves to be very competent figures over the course of the story. Vitos in particular goes from simply being a casanova to becoming one of the Empire's best commanders.
The Usurper: Theodoros overthrew the previous emperor and founded his own dynasty.
To show just how well Skantarios reverses this, look at the two maps of the Restored Roman Empire in the section titled "The End". For comparison, the last remnants of the Byzantine Empire fell in 1461. According to the epilogue, the Restored Roman Empire survives for several more centuries, and only falls when civil war divides it into multiple successor states.
War Elephants: Byzantium fights some of these, and eventually gets a herd of their own.
What a Senseless Waste of Human Life: Skantarios remarks often at the waste of so many good men in the Egyptian generals ranks, but a particularly heart-wrenching one is the pointless death of seventy year old al-Khawalani, who charges out in the face of withering arrow fire and actually makes it to the safety of the gatehouse... only to turn around and see his entire bodyguard lying dead. With nowhere to run, he simply marches out into the Byzantine arrowstorm... the general remarks at the unworthy death of this old man.
Also of Yahya, an old general defending a city with only his bodyguard. The man kills no less than four of Skantarios' own bodyguards, who later reflects that the Sultan did not deserve such a man fighting for him.
Arrogant Kung-Fu Guy: Ioannis. While his talent is recognized by his peers, he's still not as good as Genessios or Vitos.
Bittersweet Ending: On the one hand, a bloody civil war has cost the empire Genessios, Vitos and Ioannis. On the other hand, having a young Emperor at the head of the vast Empire allowed nearly-worldwide peace for far longer than Skantarios ever did.
Manly Tears: Shed in the aftermath of particularly wasteful battles.
Efthymios: I cried many tears that day. Tears for my brother, for father, and for the thousands of valiant soldiers led astray to their deaths. Mostly, I cried for our great failure to live up to Skantarios’ dream. If Skantarios had been here, I know he would have wept with me.
Stop Helping Me!: In-Universe. Genessios and Vitos do not appreciate Vasileos getting the Pope to order a Crusade against the Mongols when they'd done most of the work already, and finish off their empire before they arrive to prove their point. The Hungarian king, aware of the dissension between the two, tells Genessios that as an ally of the Romans, he will not stand in his way if he makes a bid for the throne.