Marvel Comics' Battle of the Atom. This special story from writers Brian Micheal Bendis, Jason Aaron, and Brian Wood - along with a huge range of artists - featured the X-Men ing forces and clashing with their future selves, featuring X-Men teams from the past, present, and future.
This narrative full of time-travel disruptions was a particularly wild ride for the young mutant Bobby Drake, otherwise known as Iceman. While the Iceman of the present had already spent some time with his younger self from the past, they were both shocked to learn that the future sees them transformed into both a wizard and an Ice Hulk.
Prior to Battle of the Atom, the original teenage team of five X-Men from the past had already been operating in Marvel's present for a while, thanks to the efforts of present-day Beast. While Beast had intended to use the teens to shock his modern-day allies into realizing how far they'd fallen, he subsequently found he couldn't return the kids to their own time. Seemingly in response to this dangerous time paradox, a group of mutants returned from the future, led by Charles Xavier II and Raze, the son of Wolverine and Mystique. A Hulk-type monster acted as the group's muscle, and Bobby is shocked to realize that this nearly mindless monster is his future self.
This future team seeks to force the original five back to their own time, but Magik is suspicious and travels into the future herself with the original Beast and Iceman, where they discover the truth: they've actually been dealing with the future Brotherhood of Mutants, and their true goals are much more sinister. As a result, the true X-Men of the future agree to travel back to the present to confront them. It's with these real future X-Men that the younger Iceman meets his other future self, a wizard going by the name of the Ice Master, leaving Bobby even more confused than he was when he met the Ice Hulk.
While Bobby's confusion and distress is pretty funny, it's absolutely understandable and quite the reasonable response when someone learns that they somehow have two versions of themself in the future, and both are totally unexpected and incredibly powerful. Thankfully, Ice Master is able to provide some context: over time, Bobby's powers continually evolve until he eventually unlocks his Omega-Level potential. In the future, Bobby will learn how to create semi-sentient ice golems that he can command at will. However, one of them gained more of a life of its own than intended and took off, being controlled into ing the future Brotherhood as the Ice Hulk.
Thankfully, Ice Master's explanations help create some much-needed clarity for both Bobby and readers. Regardless, the most entertaining thing to come out of this is seeing the Icemen of the past, present, and future teaming up to take down said Ice Hulk in the story's final battle. In the end, the future Brotherhood is defeated and the future X-Men return to their own time, though it takes a while for the original five teens to follow suit.
While the Brotherhood would return to cause trouble, and Ice Master was also seen again, it's less likely than ever that Bobby will actually become his sorcerer future self, as the founding of Krakoa and the teenage X-Men's adventures seem to have put Iceman - and the mutant race - on a much different path to the future envisioned in Battle of the Atom.
