Fire Emblem: Three Houses tells the tales of four figureheads of power on the continent of Fódlan: the Adrestian Empire's princess Edelgard, the Holy Kingdom of Faerghus' prince Dimitri, the Leicester Alliance's future leader Claude, and the Church of Seiros' archbishop Rhea. At the start of the game, the player will choose which leader to follow, and no matter who is chosen, the player will end up fighting at least one of the other factions later in the story. Loyalty to their first lord is common among Three Houses fans, and debates about which of the four lords was most justified continue to this day. The thing is, debating the morality of the lords' actions misses the point of the game: if the player chooses one side, they'll see the other sides at their worst, but by choosing another side, they'll see that side's reasons for fighting as well as what it's like when their original house is at their worst.
Source：https://www.cbr.com/fire-emblem-three-houses-bad-people-video-games/
