I see the ridge, too, right near his long eyebrow. If he's Klingon, I would guess he's also part human or vulcanoid. There are no ridges on his nose, which Klingons have had since "the incident of which we do not speak with outsiders." The scarring could be from being burned, which could be as a result of torture or perhaps some explosion on a ship/planet/station say from an attack by the human James T. Kirk, the quintessential devil in these matters!I do kind of see some ridging on his forehead. I suppose he could actually be Klingon...