It feels weird that they keep acting like Tseng and the Turks are some monstrous villains because of the Plate Fall... but then ignore the nonsense of AVALANCHE's entire plot also killed just as many people as the Plate Fall did(Something Reeve explicitly tells Barret in his Cait Sith robot). Of course, with the Remake cleaning off all of the edges, it will make zero sense to now kill The Turks for the Plate Fall since Cloud and Co. are now completely squeaky clean now... fucking Nomura and the rest.
It's weird because you could say that for all of the Maesters and some even had worse outlooks than Mika did. As you stated yourself, Mika fully believed the World was damned without The Final Aeon and Sent himself because there was no more hope. That comes off the complete opposite of being a villain that deserves a beating as he's more of a well-intentioned but ultimately pretty messed up bad guy.
Jihl got absolutely fucked over to an absolutely ridiculous degree considering she's the reason why Sazh is even involved in the plot and damn near killed Vanille.
It's ridiculous we get no real confrontation with her at all and she's ultimately just fodder to Barthandelus and it's worse as Cid Raines at the very least gets a far more memorable boss fight and still matters to the plot 2 games after his death.
Like FFXIII-2 exists and she's actually a pretty damn good "monster" to use once you level her up and her boss battle is genuinely difficult(You need to kill her flunkies in a certain time limit or her LB will wipe your ass out and even then, they benefit the shit out of her anyway meaning it's either killing all of them in a real short time or killing off the most beneficial to her currently and surviving her shit after) but yeah, there's no real pathos to it either. Shame really as her design is probably the most striking out of Barth's goons.
Eh, both of them are ultimately missing the whole point if you want to fight them.
For all of Gestahl's bullshit(And he does alot of fucked up things including taking baby Terra from her dying mother and even kicking her away to basically damning the Espers by taking them with his forces for his Empire), his death by being outwitted by Kefka was ultimately his own fault. He basically saw little of Kefka despite being a monster born from his prototype Magitek soldier program and did nothing but use him as another one of his forces. So getting outwitted by him at the end(while losing all of his actual good soldiers because Kefka backstabbed all of them) was carthatic.
Queen Brahne is just weird as she literally cannot fight, Garnet will not allow anyone to fight her mom and even Alexandria was mourning her passing despite Vivi(being the surrogate character) stating he feels nothing for her death but it hurts seeing Garnet be sad. Her entire state is she got warped to being evil because of her original family(Husband and actual Daughter) all dying and Kuja swooped in and took advantage of a Queen in massive grief.
If anything, you think he would have put Beatrix on the list considering there is alot of outcry that "she got off too easily"(Which you can argue) and you never truly win against her at all(which is the point...)