Marvel Comics has always shown the Avengers as Earth's Mightiest Heroes, but that doesn't mean they haven't faced off with fearsome villains. At times, the Avengers have encountered teams of villains that proved formidable and almost defeated them. These villain alliances have lasted generations of comics, and some continue to drive Marvel's biggest storylines.
Source：https://www.cbr.com/avengers-villain-alliances-team-ups/
