Yes, Charles Xavier was shown to be walking in the beginning of X-men: The Last Stand. He was also shown to be walking in X-men: Days of Future Past, before going back to his paralysis. This continuity doesn't match and that is a widely recognized fact.
Charles was 24 and Erik was around that age, though it was never given.
Onslaught is a being that was created from the merging consciousnesses of Charles Xavier and Eric lensherr (Magneto).
Well since xmen four is befor xmen 1,2 and 3, magnito will not be in it but there is some other dude that wolverine fights. I can't tell you who it is because it would spoil the movie but I known the knew xmen 5 is all about magnito.
No, it only has one
Heres a good cheer if your the xmen who are we xmen who are we xmen how do we play xtreme
yes
It is Xmen 2, and you can get it at Wal Mart
yes in x-men 3 the last stand
No
jean luc picard professor Xavier and Jean Luc Picard are both played by Patrick Stewart.
Magneto's main adversary is Professor Charles Xavier (Professor X) the founder of the XMen and Magneto's former ally. Magneto is also the enemy of all the members of the XMen, especially Wolverine. Magneto is the founder of The Brotherhood of Evil Mutants. As such, he is the declared enemy of all humans (homo sapiens). Currently, Magneto joined the X-Men on Utopia and became one of their members. Therefore, now his enemies would be the same enemies of the X-Men.
X-Men,X2,X-Men:The Last Stand,X-Men Origins:Wolverine and X-Men First Class.