Because you like Bull Randleman in Band of Brothers

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

Both intelligent and empathetic, Remus Lupin is worn down by the weight of a secret. See them in Harry Potter Series.