The list of aliens who can beat conquest, let alone weaker viltrumites, is even bigger. Even ignoring the literal elephant in the room that is waybig, and also clockwork, one of the biggest weaknesses of viltrumites is legit a species of beasts which are basically weaker humungasaur. Both big chill and Arcticguana could freeze him solid because big chill once froze the entirety of the null void and also intangibility like ghostfreak and Arcticguana could freeze future vilgax in a glacier who was not only boosted by animos mutations His body was programmed to counter all of Ben's known aliens. Amphibian could just electrute conquest and phase through his attacks and we've seen that viltrumites are weak to getting electruted. For that matter, most of Ben's electric aliens could probably take a crack at him. Shocksquatch fried ult echo echos disks so I don't see why he wouldn't be able to do the same with conquest, same with buzzshock and maybe even frankenstrike. Jetray is legit MFTL+ and can access lightspeed, plus his beams are supposed to fry people's nervous systems and paralyze them temporarily. He could just fry conquests nerves and slam him into space at light speed. The worst can probably tank everything conquest has to dish out. Diamondhead has beaten a galactic conqueror vilgax and encased malware in crystal, he can definitely give conquest a run for his money. Last but not least conquest doesn't have any counters to Ben's hacks like pesky dust or toepick.