Because you like Samantha "Sam" Kingston in Before I Fall

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

Severus Snape is a misanthropic potions teacher with a vindictive streak. See them in Harry Potter Series.

He's an eccentric pirate making it up as he goes along. He's Jack Sparrow, savvy? See them in Pirates of the Caribbean: the Curse of the Black Pearl.