Warlock has heard enough bragging about Mage blowing up a panel     ...but you see, she says, as the room darkens and she glows green

...when it comes to warlocks, she says, with red eyes and black everywhere    *the comic panel itself has run away in fear* she's nonchalant.

..."there's usually nothing left to blow up." She does make an explosion, but just for effect. Mage is about to fall out of the frame, and is confused.