1800? explain.

I kind of have two versions of Grey, Grey and Zero, who goes by many names. Zero can die, and I use him for stories, same design, different character. Grey comes from another world entirely, his people have waged war for so long because of immortal soldiers like him that help keep the conflict going. The war is over these immortals, and when he realized that he couldn't keep fighting like this after all the death he himself has caused in his many years. So one day he made a deal with a god to be sent to a world that was in peril, and needed his help, in exchange for his immortality, and he would have no way back. So he joined up with The Saints at the start of the End War as a Ranger and has been going strong for 10 years.