Aaron Taylor-Johnson

Because if he does, then he will be the Quicksilver in the main X Men team moving forward since Evan Peters already plays his Fox X Men rebooted Timeline Universe version. Unless he dosen't want to come back and Evan Peters will play him in the X-Men since people like his Quicksliver better than A.TJ.

As Pietro Maximoff. It's time. They could bring him back from the dead....somehow. I hope Pietro appears in What If... using Aaron Taylor-Johnson's likeness.

One-Time Characters always have a chance to come back.