Jared Leto is a method actor. When he was playing the Joker in Suicide Squad, he did all manner of awful things to his cast mates because it's what the Joker would do.
In "My So-Called Life", Jared Leto played the character Jordan Catalano, the typical bad boy with hidden depths, as evidenced by his song writing abilities.
Jared Leto has a band called Thirty Seconds To Mars.
Jared Leto is still method-acting Jordan Catalono, 25 years later.