Isekai from the very gates of death.

This is the story of a man who died. And found himself Isekai'ed to the world of Teyvat, the fictional setting for the popular game of Gensin Impact. But this isn't the usual story about a bland generic self insert character. You are Lord Black. Yes, 'that' Lord Black, the lovable roguish Wizard and Dog Animagus, former Auror, and the Godfather of Harry Potter. The main thing is the fact that you just did something potentially impulsive and foolish, you just jumped in the way to save Harry from certain death and fell through the 'Veil of Death' as a result. A one way ticket to certain Oblivion. Or so you had thought...