The biggest thing for me is how a werewolf MC's power isn't just a cool bonus; it's a liability that redefines their entire social existence. That full moon curse means their greatest strength—raw, untamed force—is also what locks them out of normal human connection. They have to constantly monitor their own temper, their instincts, in a way a vampire or mage doesn't. One moment of genuine anger could mean a death sentence for someone they care about.
I always think of Remus Lupin, honestly. The man was brilliant, kind, a fantastic teacher, but he lived in poverty and isolation because society saw him as a monster first. His vulnerability wasn't just physical during the transformation; it was this permanent state of being one slip away from being ostracized or worse. The best stories dig into that tension—the pack might offer belonging, but it comes with its own brutal hierarchy and expectations that can feel just as confining as human society. The power doesn't solve loneliness; it often deepens it, because you can't ever truly let your guard down.
And the physical cost! Exhaustion, pain, the sheer disorientation of shifting—that's a kind of vulnerability superheroes rarely deal with. It grounds the power in something messy and real.