There have been many horrible people in the past: Hitler and Pol Pot are two who had a lot of people killed for basically no reason.
Villain is a noun and does not have a past tense.
black widow and dr.hare
megatron
Batman's worst enemy is the Joker. Another villain is Two-Face
People usually do not set out to be evil- they just act that way because they think what they are doing is right. Evil people are just ones who make bad choices. Often- they are powerful people who start to think that they can do whatever they like because of that power. That sort of thinking is "the road to evil".
It is the past tense.
it depends on what you do with the villain[s] when you catch them
Calendar man, MAD HATTER, the ventroloquist, maxie Zeus
Hitler was the worst person to ever walk the earth!
find the maze near the mine and follow the traces of corn
Hurricane Katrina
For the melee stages hm? probably the worst stage is the past yoshis island stage.