What are your thoughts on Pike... But he's from the Mirror Universe?
Mirror!Pike: The Inverted Paragon
I have actually thought about this a lot and how the way Pike is as a human being could be inverted in the hands of the Terran Empire. His fundamental traits both grate against the things the Empire stands for and could also be their deadliest weapon.
Fundamentally, Pike is a paragon character, like Superman or Captain America, he eats, breathes, and bleeds what he believes in. He is totally devoted to the ideals of the banner he flies under. We know in the Prime universe he'd be more than willing to give everything up, even die for Starfleet's cause. He is oath and conscience, service and sacrifice, through and through.
In representing the pinnacle of what he stands for, he inspires borderline fanatical loyalty that is only matched by his own devotion. He is, canonically, Starfleet's poster boy and wasn't even aware of it. This can be as much a danger as it is an asset, especially in the Mirror Universe. In my mind there are three ways he could go in this timeline, I call them Claude Frollo, Leto Atreides, and Scorpia respectively. I like all the options so I'll describe them each in turn!
Claude Frollo (True Evil Paragon)
This is the Mirror Christopher Pike that knows exactly what he's doing, he uses his abundant empathy without Prime!Pike's compassion to manipulate and radicalize those under his power. To the point where they are too worshipful and terrified to even think about killing him to go up in rank. He seeks to be feared and adored, and has a reputation for avoiding the more brutal ways of punishing subordinates and taking in soldiers who don't fit the standards of the Empire's purity. In this characterization, Spock is his Quasi Modo, his pet project. Most likely he would seek to prove that Human mutts can be weaponized against inferior races. He may even be so charming as to convince non-Human worlds they'll be safer under the Terran Empire's banner in subordination than facing a pitiless galaxy without their protection. The secret to his success being that he genuinely believes the xenophobic, paranoid bile the Terran Empire stands for, he's just not stupid about it. All that being said, I do think he'd be too loyal to the order of things to make a bid for Emperor, he's content with his little cult/fiefdom as it stands. Unless an opportunity opens up like, say, both Georgiou and Lorca being dead, arises for him to take the throne. This Pike probably also kills Una for being an Illyrian spy and La'an is his right hand with all that Augment Descendant clout and treats her like a princess and daughter to maintain her loyalty.
Leto Atreides (Reluctant Evil Paragon)
This variation of Mirror!Pike is significantly less self-aware and maybe a bit more critical of the Terran Empire's ideals but still willing to play the game because, let's be real, power is one hell of drug even for the best of us. This version seeks to make the Empire better from within, which is ultimately a fruitless task because Terran imperialism is rotten to the core. I'm sure this Pike while definitely equipped with plenty of subconscious racism, is probably as not-xenophobic as he could get away with being in this depraved system, the peak example being making room for Spock to climb the ranks. He's well-loved by his crew, but too hesitant with violence to not get himself killed. Either a subordinate takes him down OR he becomes so well liked by his Terran crew and beyond that Empress Georgiou saw him both as a threat and dangerously too soft, and killed him. This Pike is a dead man before the Discovery even got trapped in the Mirror Universe. Which might explain why Georgiou is so uninterested/unimpressed with him when they interact in season two.
Scorpia (Ignorant Evil Paragon)
This Mirror!Pike believes in the Empire because he's been completely brainwashed by the propaganda it spews. Having been raised on Terra Prime, would have no information to the contrary until he joined Starfleet. I'm sure he spends a solid chunk of his career stifling his cognitive dissonance and sense of honor enough to survive, and eventually thrive as bits and pieces of his soul get ripped out of him. Until eventually something just snaps and he goes completely rogue. Which ultimately makes him either dead, a prisoner of war on either the Empire or Rebellion's side, or hiding somewhere. Mirror!Una probably helped him defect considering she's either an Illyrian who thinks she's human OR an Illyrian spy. Not optimal but at least he isn't a monster? Kinda, he probably had to do some messed up shit to get to Captain in this universe, but at least he feels remorse in this variation! Yay?