Because you like Katherine Murphy in Just Go With It

A wildly brilliant detective, Sherlock Holmes can figure out everything except how to interact with other human beings. See them in Sherlock.

His murderous megalomania aside, Loki is quite charming. Just don't mention his strapping older brother; he's a tad jealous. See them in Marvel Cinematic Universe.

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

A daring conman, Flynn Rider is so charismatic that you might not mind when he steals from you. See them in Tangled.

When the Sorting Hat touched Draco Malfoy's head, it placed him in Slytherin, a house that has turned out more dark wizards than any other. See them in Harry Potter Series.