Because you like Kafuka Fuura in Sayonara, Zetsubo Sensei

Light Yagami has a plan to make a better world, and morals won't stop him. See them in Death Note.

Brilliant, violent, and only a little insane, the Joker doesn't listen to anyone except the voices in his head. See them in DC Extended Universe.

L is enigmatic, child-like, and one of the smartest people in the world. See them in Death Note.