What happens when the best, most noble mutant, Prof X, decides to get a little bad? Onslaught is a villain unlike any the X-Men have faced before. And when they can't handle the him, the Fantastic Four and Avengers find out they're even less of a match. Even the villains of Marvel have to try to stop the single most destructive mutant of all time (who grows more powerful collecting the powers of more mutants along the way). Maybe this is why humans fear mutants so much.
Written by: Mark Waid and Scott Lobdell
Illustrated by: Andy Kubert