There's not much to get Arima was the One Eyed king, (Glycoma in one eye, and a demi human part ghoul strongest one around), Kaneki being the one that "killed" him fulfilled eto's request and ascended the throne as the One eyed king, the ghoul that gives hope to all other ghouls the one that killed the undefeatable calamity that was Arima which was her plan all along. Re means King.
Wait, then I got it right on first read. Thought there was something I was missing.
Thanks!