I posit that the universe screeches to a halt at the Crusader's will.
Why?
Well, what actions can anything in the universe take while the Crusader continues to roll its infinite damage? Why, immediate ones of course, but then things only get one of those, and we're talking about a few billion immediate actions against infinite dice rolls. Once the everything in the universe that is even capable of taking an immediate action has taken its action, the Crusader will still be rolling damage.
Why?
Well, if he stops, the Frenzied Berserker's still alive, right? The moment the Crusader stops rolling damage he's arrived at a finite number, and he's completed his action. And if he ever does that he's screwed, because the Berserker's gonna tear him in half six ways to Sunday. So the Crusader better damn well not stop rolling his damage. And if he doesn't stop... nothing else ever happens. The Universe freezes in time as long as the Crusader wills it.