Battle of the Atom is a 10-part Bat Family Crossover published by Marvel that debuted on August 28th 2013 and ran through the All-New X-Men, Uncanny X-Men, Wolverine and the X-Men and X-Men books until October 30th 2013.The story begins with Magik traveling to the future and witnessing a group of mutants fighting Sentinels. In the present, after Teen Cyclops is nearly killed in a Sentinel attack, which almost rewrites history and results in the modern Cyclops disappearing for a moment, the modern X-Men decide to send the original five X-Men back to their own time. However, before they can, a future team of X-Men, consisting of Kitty Pryde, Molly Hayes, Xorn, Deadpool, Beast, Xavier (Legion's son and the grandson of Charles Xavier) and Ice Hulk (Iceman), appear to do the same, as the presence of the original X-Men in the current timeline will result in disastrous consequences. However, they do not tell anyone what these consequences actually are, thus making it hard for some to trust them. Also, they shield themselves from telepathy, making it even harder to discern if they are being truthful. Needless to say, all is not what is seems, and conflict ensues between various factions of X-Men, some believing that the original five X-Men should be sent back, some believing they should make the choice themselves, and some not believing the future X-Men.
In addition to the usual X-Men tropes, this series contains examples of:
Not an even divide, mind you, but the combined group of modern X-Men and future X-Men has Kitty Pryde and Rachel Grey opposing sending the original X-Men back to their own timeline against their will.
This would also count as being a split with the X-Men of the adjectiveless X-Men book, as Storm is all for sending them back. Rogue and Psylocke appear in the story after a choice has already been made.
The original five X-Men already lost Angel in All-New X-Men, and now, Jean and Teen Cyclops are on the run. Teen Hank just wants to watch what happens, but seems willing to go back to his own timeline.
Cyclops' team of X-Men is divided, with Scott and Eva Bell wanting to help Jean and Teen Cyclops, Emma Frost and the Stepford Cuckoos and Magneto wanting to send them back, and Magik going off on her own.
The real future X-Men had a vote to decide if they would help Magik drag the team that went to the past back, with Kymera and Piotr for, Jubilee against, and the rest unknown. They came to the past so one side won at least.
Axe Crazy: Raze, who likes any plan that involves fighting or killing.
Back-to-Back Badasses: In Part 9, if a character has a version of themself on their team, they fought alongside them.
Bad Future: The future X-Men came from one. But not really. Rather, a same future, as the X-Men still exist, and while they've come a long way (namely, a mutant President), it's still not enough (since the mutant president, Dazzler, is killed), and mutant persecution is apparently still in force. Bad things still happened though, which is blamed on both the presence of the O5, and the schism between Wolverine and Cyclops.
But for Me, It Was Tuesday: Triage accuses Scott and the other X-Men of having this worldview when they don't seem to understand why he's so freaked out that he brought Young!Scott back from the dead. It's not flattering.
Call Back: Nick Lowe confirmed on Twitter that the Jean Grey School seen at the end of Part 5 is the same one from Wolverine and the X-Men issue 29.
This isn't the first time Beast has turnedevil in a future or alternate timeline.
Despair Event Horizon: The fake future X-Men seem to have had one when Future!Dazzler died. Or at least Future!Beast.
Downer Ending: The present and past X-Men survive, but a couple of the future X-Men are killed in battle with the new Brotherhood. On top of that, it comes out that someone at S.H.I.E.L.D is manufacturing Sentinels. Several of the new Brotherhood members survive and are loose in the present. The schism that divides the team is widened further as Kitty and the O5 X-Men join Cyclops' side due to Kitty being unable to trust the JGS.
Evil Cripple: Future!Xavier becomes one, thanks to Future!Colossus.
It's Personal: After telling a masked Future!Jean (whose identity she did not know at the time) where Teen Scott and Jean are, and letting her knock out Jean, Emma decides to fight Future!Jean, with no reason other than that she is Jean.
Legacy Character: In the future, Jubilee adopts the title of Wolverine, Wiccan becomes the Sorcerer Supreme, Quentin Quire becomes the Phoenix and Future!Jean takes the identity of Xorn.
Mythology Gag: A throwaway line that non-Runaways readers wouldn't really pay attention to.
Molly Hayes: Trust me, guys, you have to stop running.
Reason You Suck Speech: Wolverine and Cyclops both attempt to give each other one at different points, but in the last part, Xorn!Jean gives them both one about how Schism lead to the X-Men becoming a mess and that they need to get over themselves.
Set Right What Once Went Wrong: The future X-Men's (or rather, the future Brotherhood) goal, which is to send the original five back in time. Though in fact, it turns out that it was because Xorn!Jean has seen so much pain that she's decided she wants to erase her own existence, not because any of them do anything wrong.
Shaming the Mob: Deadpool, of all people, to stop the fighting between them all in Part 5. He admits he was lying.
Ship Sinking: Kitty has officially left the JGS and joined Cyclops' side. The chances of Kitty and Iceman getting together are now pretty slim.
Shout-Out: The presidential inauguration in Part 6 has the slogan "Yes We Did" all over the place.
Start of Darkness: The death of President Blaire is played up as being Future!Beast's.
Tragic Keepsake: Future!Colossus' Soulsword, given that Future!Jean revealed that Magik killed herself in their timeline.
Villainous Breakdown: Future!Xavier suffers one when he learns that Teen Iceman and Teen Beast left the Jean Grey School. He proceeds to Mind Rape Bling for their whereabouts.
Deadpool: It was a good speech. It's a shame it was all a lie.
Writer on Board: Jason Aaron's contributions to the story seemed to be filled with X-Men hating Cyclops and his side, including making mean-spirited and childish jibes his way in moments when they have FAR more important things to be dealing with. Not only are these moments not present in anyone else's parts (save for one Bendis-penned scene which has Xorn/Jean call them both out on it), but two of the characters who are shown to be supportive and appreciative of Cyclops' help (Kid!Cyclops and Kitty), actually join in on the others with the pointless jabs in his parts. His epilogue is also used to shoot down any peace between the two sides that may've been born from the story, as noted above. It's pretty clear Aaron does not like Scott.