I love twst's ability to make even the most unhinged, ridiculous or stoic/"mature" characters feel like actual teenagers. Even Azul, Malleus, Jade, Vil, Riddle, etc have their moments that makes you remember the fact that oh yeah, he's just a seventeen/eighteen year old kid.
And then that makes their backstories and current situations or treatment of themselves even worse. Ouch.
Wow... so Malleus' signature spell is literally indestructible unless you manage to incapacitate him. That in itself is pretty much impossible as well, because everything within his domain literally obeys his every will; laws of physics be damned, common sense be damned. He could turn air walkable and earth untouchable if he wants to. He is the absolute god of his kingdom. If nobody stops him and his domain manages to swallow the entire world, then it's game over for everyone.
That, and if you actually manage to destroy his magic in that .2% chance, then everyone--literally everyone will have their souls destroyed along with it.
I think this is a very, very interesting condition. It plays perfectly with his false god role because 1) Everyone and everything obeys him, and 2) Everyone dies for him. Just like how people die for their gods throughout the entirety of history.
So Lilia's advise to everyone really was serious. "Let sleeping dragons lie." because there's no escaping a dragon awoken.