10 Most Brutal Murders The Joker Has Ever Committed
3. Now Who's Stupid?
When Batman gets hold of Alexander Luthor Jr. after a fight that killed Superboy and seriously injured Nightwing, the caped crusader nearly abandons his no-kill rule. The situation is ended by Wonder Woman, who reminds Bruce that revenge is "not worth it". Unfortunately, the gift of mercy didn't last for long.
Once the battle for Earth has finished and Metropolis starts to rebuild, Alexander bumps into certain death in an alleyway. He is already beaten and downtrodden by his defeat, but his bad mood wasn't going to last much longer.
He is first confronted by Joker, who sprays him in the face with acid and fries half of his face off. Writhing on the floor in agony, his father emerges from the shadows and showers him in false pity. In retaliation to Alex underestimating his father's help, Lex had hired the Joker to take out his son.
The Joker was happy to oblige, as Alex had left the villain out of the plans to merge Earth Two and Earth Three. After the brief interaction, the Joker points a shotgun at Alex's melting face and pulls the trigger. The two walks away, with Luthor quipping "Now who's stupid?" to the corpse of his son.