I still wonder how the gods were defeated considering they could create new worlds if they just will it i mean the goddess used 0.01% of her power to make touka get to lvl ten so We can assume her mana level are in the 100,000 which are far higher than any necromancer so far. Some gods might be in the 50-100 range but I don’t really see them losing if all they need is one god to just kill everybody.
The only thing I can think of a reason why gods gave up is the demon and necromancer held the humans hostage but then again they could have easily protected them too.