Avengers: Doomsday - Character Breakdown
7. Magneto

When the names of Kelsey Grammer and Patrick Stewart were announced for Doomsday, of course there was excitement. However, these are two names that have appeared on MCU credits before. Fantastic news, absolutely, but seeing Ian McKellen's name took things to a completely different level.
McKellen has not made an appearance as Magneto since Days of Future Past in 2014, and his name on the back of that chair signalled the true return of the X-Men. It will be incredibly interesting to see what kind of take they have for Magneto, since there is such a wide range to choose from.
Erik Lehnsherr began as an X-Man himself and best friend of Charles Xavier, before going on to form the Brotherhood of Mutants and start a war against humankind. After the timeline retcon, he became one of Apocalypse's (Oscar Isaac) four horseman, however by the end of Dark Phoenix he was still on speaking terms with Charles. There is absolutely no way of knowing what Magneto went on to from there.
So, even if the Doomsday version of Magneto is the one we all know and love, he may be a completely different character by now. Or, if it's a different variant of the villain, there is no reason why Marvel Studios shouldn't bring him in as a version of Wanda and Pietro Maximoff's (Aaron Taylor-Johnson) father. There is no end to the possibilities.