C
The bay forumite Magmacube Underscore Tee-Ar has come! A great cube made of magma. It has sharp teeth and giggles maniacly. Beware it's deathly heat!
Magma attacks around randomly. Snoos flee randomly in the initial confusion, but soon enough, they gather in groups and start to move their antennae in unison. A rain of blue arrows come down on Magma. He realises that they are attempting to downvote him.
A snoo is pathetically weak when alone, but they are seldom alone. A few thousand snoos, like how many Magma is facing off against, are a legitimate threat. But Magma's being isn't very reactive to this form of magic. Centerians tend to use approval magic to uplift or downthrod what they don't like, as it is a part of their being. Magma has no such components in him. The downvotes end up being mostly useless.
Snoos quickly notice this. They start to coalesce into different structures to cast something more complex. But Magma doesn't lets them.
PCM: 4
MC: 20
[VOLCANOES] fills the room.
Before they can react, the snoos melt away into little puddles of multicolor goo. Then the metal structure starts to soften. The climate control devices fail and the metal pillars sag and weaken. The ceiling melts and collapses onto the ground, turning into a lake of molten metal. But then, the heat lowers, the lake solidifies, and the flowing metal stays put.
Magma stops casting. He is very exhausted. It is a foreign thing for him to be exhausted. Sphere magic no longer infinitely comes from the outside. But Magma has to produce it himself. Consequences of being in a place far from home.
Magma could try to continue his rampage, or he could leave off into some other subreddit. Or he could attempt something else. Something more... sneaky.
A: Continue rampaging.
B: Leave through the molten hole in the ceiling.
C: Shapeshift into a snoo and start to scheme.