If you were a hero & had to rid the world of supervillians: who would you view as the biggest threat

[Ed MOTHEREFFING G]

lets SEPERATE DC and MARVEL universes for this conversation

If you were to stackrank the threats villians pose to earth's safety and peace, who would you rank as the biggest THREAT to the world...the one you'd have to take out (you can read that as KILL, imprison, send to negative zone, whatever you want) first.