Ainz Nuclear Blast

First of all, it had a very large area of effect. It was superior to almost all other
spells in that respect. In addition, this spell also generated all kinds of negative
status effects such as poisoning, blindness, deafness, and so on, but anything of
the Evil Lord’s level would be able to resist it with their raw statistics alone and
the Pleiades’ equipment ought to have made them immune to all these effects.
The main reason he had chosen this spell was because it also possessed a very
powerful knockback effect.
Of course, Ainz would also be damaged by this spell. While friendly fire was
off in Yggdrasil and so using a spell this recklessly would not be a problem, right
now he would be hurting himself. Even if his magical defense was very high,
there was no need for him to go out of the way to take damage to cast his spell.
Rather than act like a suicide bomber, he ought to have chosen another spell.
However, Ainz had already worked it out.
If he expended the [Body of Effulgent Beryl] spell to stop all the bludgeoning
damage, the fire-elemental damage would also be negated, which would mean
he would not be harmed. In addition, all those negative statuses were ineffective
on the undead.
In other words, Ainz was undamaged by the spell.
If he completely resisted its damage, the knockback would not take effect
either, and so Ainz was the only one left standing in the heart of the explosion.

- Overlord; Vol 13; Chapter 5