Final Fantasy Tactics Advance featured the single most insufferable, lunatic protagonist I've ever encountered. They didn't make Marche that way on purpose, but it can certainly come off like that.
This twelve year old kid is transported to a storybook world based on Final Fantasy and his emotionally traumatized friend's wish for his Mom to be alive again. His first reaction is that this place isn't real and he needs to go home. It turns out that the only way to get back to his "real" world is to destroy this one and everything in it. He doesn't have any particular rationale about why what he's doing is right. He thinks that everything around him is a fantasy and as such cannot conceive that there may be more at work than he perceives. All he has is that there are pillars supporting this fake world and he needs to destroy them so he might be able to go back to the real world.
Also, he's clearly doesn't understand the consequences of his actions, as evidenced in the dialogue of one of the Jagd battles. Jagd are the only places in the context of the story where people you fight in a battle actually die. Perma-death happens only in these lawless places.
Enemy Ninja: A hit-and-run? Nope, don't know anything about it.
Marche: I know you do! You won't go unpunished for this!
[Battle begins. The enemy ninja is defeated.]
Enemy Ninja: I-I'm sorry... I didn't mean to run after the accident...
[All the enemies are defeated.]
Marche: Apologize to Nono. And don't ever do it again.
[Screen fades out to World Map.]
Marche: [Hit Again] went well. Now for the next one!
He just told the corpses of his slain enemies to APOLOGIZE and never get in an accident again. THEY ARE DEAD! CADAVERIFFIC! They are no more; they have ceased to be.
So when I got to a part of the story that has someone dropping truth bombs on this deranged mass murdering psycho path, I ended up having to fight Babus under extremely unfavorable laws. I actually lost a fight for the first time in the game and Marche went to prison. I could've loaded it up and done it again but...that was the ending I wanted. Maybe he starts seeming less certifiably insane later, but Babus and Cid kicking the shit out of him while making him understand that they do in fact exist as they are now and that thousands of other people that did not exist in his world are here and alive, then throwing him in prison because geocide is never the answer is just too perfect. I don't know the actual ending of FFTA. I don't care. That's how that story will always end for me.