Why Leo?

I guess I see Leo in between PowerPanda's initial post and Timbo's breakdown, closer to the former interpretation. Leo admits he did willfully turn a blind eye at times, but I also think he is genuinely a compassionate, principled soldier. His fault might be trusting in an institution that is more craven than he realizes, but I think at the core, he does want to do what is right and isn't wrapped up in being a good soldier for the Empire's stake.

I can't read that Doma situation as negatively as Timbo, though. Leo, an officer, was recalled forcibly from the operation he was leading. He can't disobey orders and not leave Kefka to himself, because even if he wanted to, his men would never follow him. We see what Imperial soldiers did to Celes and she was a general. I can, though, take a more cynical view of his later actions if I'm in the mood for it.

Also, a big part of the problem with how to view Leo is that since the game is from the perspective of the rebels, we are not privy to his actions outside of what is seen, and from what is seen Leo does seem to be a soldier with true honor, just misguided. He could be actively ignoring what is happening in the Empire, or maybe he is feeling guilt after the fact end overly blames himself for his actions.

It does serve the narrative of the game for him to die, rather than live, not because of Leo's own faults, but because the death of Leo goes to show how depraved Gestahl and Kefka are, not only to fake a truce but to trick and kill off their own ally for being too principled. Yes, Leo may have died in some part due to trusting the Empire, but let's be clear: he's a sacrificial lamb first and foremost who just happened to be on the wrong side. To me, he's more of a victim than a tragic hero.

But everyone loves the heroes who for the most in media, and reviving General Leo is pure wish-fulfillment. That's why he's chosen.

Hubristric characters like Leo are very often honorable, moral, and compassionate because they need to be able to connect with the audience. Leo is almost a good person, but his "blind eye" is a huge flaw. I honestly, believe that Leo had more respect than anyone in the Empire. Had Leo stood up for what was right he may have been able to end the war ages ago. He could inspired his men to abandon the empire and lead a coup to stop Gestahl. He could have dealt with Kefka on equal footing. He could've struck down Gestahl before Kefka was given his infusion. He didn't and that's why he's hubristic.