[shmaster]

大魔王が倒せない
It is from the same author and within the cosmology as Instant Death.

Spoiler:

She functions the same way as Yogiri do. Because they are the absolute finality, whatever they say and do supercedes everything else when a World Conflict occurs and the reality well adjust itself to it accordingly. But because they are both the finality, they can't supercede one another.