Really? I think the last three panels are exactly why the Magneto of Planet X worked. In his zeal, that Magneto has become exactly the kind of monster his former slavers were, as has always been his greatest fear, as is exactly what has happened here. Only difference is that in Planet X he is too old, too outmoded and too far gone to "appreciate the irony" as it were, of his deeds. He has taken his ideology to its outmost extreme but after years of fanaticism, he doesn't really know why anymore. That is exactly the same Magneto as pictured above.