Can Nul break Monarchs armor

Same scenereo as Superman prime but monarch cannot fight back

I'd say yes. He crushed an enchanted Asgardian hammer when he got sufficiently angry. I'm sure he could do it if he got angry enough.

No

Poster or character?

not a chance

What is the metal called Dilustel? Why wouldn't he be able to if he tore through Adamantium netting like tissue?

He can break it.

In his dreams, maybe.