Joker has not killed millions (in non Alt universe stuff) but if we're talking body count then Mongul killed an entire city of millions.
Norman has: Had a one night stand with Gwen and got her pregnant with his children, Killed Gwen, took over S.H.I.E.L.D. , forced Peter's best friend to abandon him, and that's just the stuff I remember.
"Anything substantial"...Like what? Like trying to BECOME Flash and then murdering Flash's wife when it fell apart?
Scorpion and Rhyno are not shit, Hammerhead is a typical gangster, the rest are feh.
Rhyno is a grown man in a rhyno suit that charges at things. He is shit. Scorpion is infinitely better, but not much.
Joker has Killed Jason todd, which yes did affect Batman on many levels. It caused him to become very risky, almost to the point of killing himself in combat. Batman needs a robin, it keeps him from going absolutely batshit insane. The only reason Tim became Robin was so that Batman wouldn't end up killing himself.
Joker also Paralyzed babs, and submitted multiple people to insane levels of torture.
He has the ability to convert people and twist their thoughts because half of the stuff he speaks does in fact make sense. He is one of the most manipulative villains aside from Lex.
Joker especially in his last arc even in defeat damaged each individual member of the bat family psychologically...most to the point where they don't trust Bruce anymore...and he did it as a joke. He had no information on them at all.
Joker has maimed, killed children, used children as weapons, blown city blocks up, poisoned people, and for really no purpose other then to cause chaos. All the while, when he explains his motives, it makes sense. It's really fucked up.
