It's on the tip of my tongue.
What's the name of the side character from the underworld who calculated the trajectory of a cigarette to hurt the main character and saved a girl from hell that was kidnapped and later on becomes a good guy?
Picture unrelated, but we can start passing around chocolate because it's close to that day, r-right?
Kaede a shit.
He had long hair and was a physics master if that adds anything to your memory.