He can't hear the warning from Bull, but he can see the object being thrown and turns quickly, dropping down with Beleth to cover her with his body. He would save her; he could make sure she wouldn't die like Ashaad had died next to him on Seheron, torn apart by an explosion as well.

Korrin's barriers were the only things that would be able to save them from this, and that still didn't mean that the grenade (or whatever it was) couldn't take out the ceiling as well.

Or...?

"Freeze it!"

Ice magic might stop the fuse.