So, okay. Well, if we go back a long time ago in a galaxy far far away when Magneto had a soul, he had two kids named Wanda and Pietro. Or, Scarlet Witch and Quicksilver? They're Avengers, only not in the universe that some of the Avengers here are from...
Anyway, skip a lot of timelines and events, the Scarlet Witch had two children, whom she sort of wished into existence. Only it didn't last, and the souls were reabsorbed by Mephisto? And then, we were reincarnated into completely different lives...
Which is how Magneto is sort of absolutely my grandfather. If we're going like spiritually-soul-power-lines???