Warning! This article contains spoilers for X-Men Red #2.
Marvel's X-Men relaunch has revealed Magneto's saddest secret. Max Eisendhardt has lived a long life, and he has seen more tragedy than most. Magneto's story begins back in the Holocaust, when he and his Jewish family were taken to Auschwitz concentration camp. But that was only the beginning of Magneto's suffering, because he swiftly learned what had happened at Auschwitz could happen again.
When the Second World War was over, Magneto headed to Ukraine, where he settled down with his beloved Magda. They began to heal, as much as anyone can ever heal from the kind of tragedy they had suffered. They married and found happiness as a couple, as well as a measure of contentment when Magda gave birth to a daughter, Anya. As established in the story "A Fire in the Night" by Chris Claremont and John Bolton from Classic X-Men #12, Anya became Max's hope, his talisman, making everything he had endured worthwhile. Unfortunately a fire broke out at the inn where they were staying, and a mob prevented Magneto from rescuing his daughter from the blaze. Magneto avenged himself, killing every citizen of the town where they were staying, but at the cost of his marriage - for Magda fled, grief-stricken and horrified at everything she had experienced.
X-Men Red #2, by Al Ewing and Stefano Caselli, adds another layer of tragedy to the story. Scarlet Witch recently used magic to enhance the Resurrection Protocols, allowing mutants who had died before Professor X created Cerebro to be resurrected as well. For a brief moment Magneto has hope, believing Anya can finally be reborn. But, to his heartbreak, Magneto learns Anya can not be brought back. She had no mutant gene, meaning she is outside the boundaries of Scarlet Witch's spell. Anya is lost - and she will never come back.
This, it seems, is the real reason Magneto recently left Krakoa's Quiet Council. To Magneto, Krakoa has been filled with the promise that everything he lost could one day be regained. But when he learns Anya can not be reborn, the mutant paradise becomes a Hell to him, with every resurrected mutant a reminder of the reunion he can never have. Worse still, Professor X's habit of wearing Cerebro all the time - the tool that was so essential to the first Resurrection Protocols - would mean he can never even look at his old friend.
There's a deeper level to Magneto's grief and loss, though. He has dedicated his life to the future of the mutant race, believing he was acting in Anya's honor, and he became a mutant supremacist and fought for mutants to rule. Now, to Magneto's sorrow, he has learned his daughter was never a mutant at all. Magneto's dreams are dust, and it is no wonder he has seen the need to seek refuge with the X-Men on Mars, literally an entire world away from the paradise he tried to build.