User blog comment:SethRollinsBabyFace/Who do you think It's Final Boss?/@comment-26441687-20160313141447/@comment-25707465-20160313142916

I'd bet a solid 20 on the last theory, with Luka choosing which side will help you take the true last boss.

I mean, there's enough evidence and pattern to say theres's two (and possibly 3) major factions for a war. I don't think said war will be the game's last arc, I would rather bet on the central world's Tartarus being saud last arc.