What the fukk would Kingpin do if he was to go up against Doom, Magneto or Sinister? He's just a fat guy who likes ascots and money.
Why are you trying to match Kingpin up against them? This ain't about that.
And The Hood is one of the most bullshyt characters in existence so a Hood/Joker meeting would probably end with The Joker in possession of that magic red riding hood cloak.
It would be some PIS writing to give Batman/joker fans a handjob. The demon would suddenly be like " Let me give the Joker all of your power for no reason. Cause he craaaaazzaaay." You cats would swear it's the greatest shyt ever.
The Joker would be just as major a villain in The Marvel Universe is he were the nemesis of a Daredevil, Captain America, Spider-Man type character. Why this is even an argument that you dudes keep wanting to have is ridiculous.
He'd be a Moon Knight/Ant Man/Ghost Rider villain.
Dumb ass writing would be like Prof X going crazy cause he read the joker's mind
Ghost Rider's penance stare don't work cause Joker feels no remorse
Wolverine can't smell him
She Hulk: oh my god, Joker just escaped from the county jail!
Iron Man: ...... okay.