Uncanny X-Men, Vol. 1 #202A (1985)

Secret Wars II - X-Men ... I've Gone To Kill -- the Beyonder!
Rachel has decided to take out the Beyonder, and the rest of the X-Men try to stop her from getting killed. In the process, one of the future's more advanced Sentinels is sent back to the present, representing another level of threat for the team to deal with.
Release Date: 1985