They didn't axe this? The way this manga diverged from it's source, I kind a figured this was killed off. It skipped a bunch of things and changed up how events flowed to get to this revelation faster in the source. So I just assumed...
In the WN the mail explains the evil god of labyrinths did try to take him as his digitised form as the green emerald dungeon master and a good aligned god interfered and stopped Schwartz from being mutated into a dungeon master.
@eng1 he was supposed to be the lord, but somehow it's failed since he ended up transported to another place with a normal human avatar. Currently, he's not a dungeon/labyrinth lord so he got attacked as normal.