Bro joker makes darkseid look super tame lets see he
Beat a child to death with a crowbar (jason)
Crippled the police chief's daughter (barbara)
Tried to poison a kid with a cookie (same comic as barbara getting crippled btw)
Forced party guests including kids to eat sergios dads fingers
Quite literally revived and killed batman again and again upon unlocking god like power
Nuking all of metropolis and killing supes baby and lois
The constant abuse of harley quinn
Kidnapped damien and ran people over while he was still in the car
Trying to explode people on christmas
And more