@Riger I'm pretty sure it was revealed in the sixth light novel's prologue? Or during an intermission? I don't exactly remember when but it was definitely around that time in the LN. I don't know about the WN though
(Edit: And the whole Veldora is back business was at the end of the fifth LN)
Why are all the cool manga I read have to be so damn complicated with each chapter... I've already read the spoilers for this one long ago, and this one is taking a similar turn to Magi, just getting too complicated with more high level bosses who basically control the world and MC got turned into some other being.
@Owyn@Dagger Nope, what Dagger said is not correct in this case. What dagger is referring to is 魔神, but the term used here is 魔人 which basically just means "magical/demonic person".
@Owyn
For those who are interested in what the term "Majin" means, here is an explanation straight from the official English TL for the manga (at the end of the official English version of manga volume 3):
Unlike many of the terms for the Fantasy races of this world (e.g. dwarves, elves, goblins), this word is not originally Western in origin, but Japanese. The Kanji mean "wicked/magicaI" and "person," and they refer to a being who is human-like but also possesses a magical nature. In real-life mythology. the term majin is most often used in Japan to refer to beings such as the Indian asura or the Arabian jinn or "genie." A famous example of the word in fiction would be Majin Boo From Dragon Ball.