The main character of Raphael Cain in the TV series The Immortal (2000) I think fit this tropes. His father-in-law, Yashiro, gives him the power to swear an oath that so long as there are demons walking the Earth, Raphael shall live as long as it takes to send them all back to Hell.
The main character of Raphael Cain in the TV series The Immortal (2000) I think fit this tropes. His father-in-law, Yashiro, gives him the power to swear an oath that so long as there are demons walking the Earth, Raphael shall live as long as it takes to send them all back to Hell.