Basically the idea of this war is all servants had their alignments shifted from traditional depictions. Not quite alters, as some are so wildly different they’re borderline original characters completely, or borrow from incredibly rare lores. Also probably my most offensive set of servants for the Avenger’s and Ruler’s identities.
Saber: Lady Kai, of the Sengoku period. Eldest daughter of Narita Ujinaga, saw her father’s disappointment in only having female heirs and took to being a warrior to keep daddy happy. She’s basically a mordred face, ironically, as the source material she was cited as "The most beautiful woman in east Japan". Her twist is she’s kind of sexist and puts men above herself, and she doesn’t mind being called female, but puts men above women all the same due to the circumstncces of the war.
Lancer: Guan Yu, of the three kingdoms period. A man that needs little introduction, but for those that do, basically imagine the baddest of the asses on the “good” side of the romance of the three kingdoms. Now imagine he let his deification get to his head and the fact his side was basically pro-suppression of the peasants and cue a very cruel and selfish demigod.
Archer: Belle Star, Queen of the Oklahoma Outlaws, a crack shot, pianist, competent rider and all around smooth business woman, she’s summoned as a good guy by manifesting the romantic ideals of what an “outlaw” is.
Caster: Baba Yaga, Original, I know, but she’s based on obscure tales, more polish in origin. She’s an older woman that is sometimes strict, but will gladly reward anyone that does her a favor ten fold and ultimately wants to protect people.
Assassin: Marie Curie, a genius scientist, two time nobel prize winner and all around wonderful woman...that secretly disseminated radiation poison throughout tens of thousands of households without meaning to, causing her to manifest as an avatar of the radium craze she caused.
Rider: Mah boi, my homie, he who they did dirty: Lu FUCKING Bu. He isn’t just a screaming grenade with zero personality, here he is an authority rejecting rebel that represents resistance of corrupt governance systems. (Fun Fact, Liu Bei a “good guy” from the source material ate a dude’s wife, and this was considered a heartwarming act on the dude that killed his wife for letting Liu Bei ate them...maybe Lu Bu was right to say fuck emperor’s that aren’t him) Absolute stone wall with zero emotion except for his Master whom he sees as a connection to the modern world.
Now for the controversy. Once again, berserker has been kicked, for reasons. We’re starting with the less controversial choice and then we’ll get into it deep.
Ruler: Saint Patrick. Apostle of Ireland, and famous for clearing the snakes from Ireland. Obviously he’s on the “bad” side of the switch, a shortsighted man that wishes to purge all pagans from the earth by any cost. No real desire to help anyone that falls outside of his impossibly narrow definition of Christian doctrine. Pretty much why EVERY summon got tipsy-turny.
Avenger: Judas Iscariot. The penultimate betrayer, the one who betrayed Christ the Lord with a kiss and most importantly: The one that enabled the sacrifice of Christ to wash away the sins of humanity with Christ’s blood. So while he’s on the “good” side of the shift, he’s still not a good person and manipulated by St. Patrick hoping to find forgiveness. His Noble Phantasm is what REALLY puts this in controversy territory. It elevates him to an agent of god’s will and promotes him to Saver Class.