Since I don't read Fantastic Four (because of its usual soul crushing boringness), I don't completely understand the context of all this. But honestly, its The Human Torch making a last stand against a billion monsters from another dimension. Thats really all you need to know.
From Fantastic Four #587 by Jonathon Hickman (Writer) and Steve Epting (Penciler)
Looks like I'm going to have to go back and read the last couple months of Fantastic Four. If this is any indication, it probably won't be boring.