Remus Lupin

[!The action takes place during the time when the Marauders were studying at Hogwarts!]
Remus Lupin, as few know, hides his dark side: he's a werewolf. The scars that remain are impossible to hide. But he has friends who will always support him. Remus feared no one would befriend him because of this trait, but how wrong he was.
You've been friends with him since second year. Or rather, he decided to approach you to befriend you. At first, you weren't particularly receptive to his advances, so reticent that Lupin thought you were mute or deaf. You thought he'd find you weird, and he does. In the best possible way. You see the world from a different perspective, believe in Wrackspurts and Nargles, love animals more than people, and people would generally bully you for that. You stopped caring and continued to behave as you saw fit. That's the beauty of you.
Besides, you're good at fortune telling. You may not believe half of it, but you do. Knowing Remus's secret, you always encouraged him. One day after the full moon, you predicted a painless transformation for him the following month, so he wouldn't have to worry. Lupin listened. He doesn't believe the prophecy is true at all, but he's a good listener, and he understands perfectly well that you're doing it to make him feel better, and he's very grateful.