"Replay", a very good fiction, witty and funny. Literally a replay of the first class events. Old Erik ends up destroying the world, and old Charles sends his conscious back in time in his younger body. He chooses a very interesting way of stopping Erik from becoming a mass-murderer. By seducing him, of course.
What he doesn`t expect though is falling hard and fast himself.
archiveofourown.org/works/267128

thehoyden - the author on AO3, everything is good? extremely likable characters and dynamics. The best is "From Westminster With Love"(where Charles is a very powerful telepath with PTSD, living in a bunker and working for MI6, and Erik is a CIA agent, that Mycroft call in, when they need mutant team for the mission), "X Marks the Spot"(Indiana Johns type of story, where Erik almost kidnaps archeology professor and they go on an adventure of looking for Tesseract and hunting Shaw in the process) and "The Tale of X"(a small fic, where Charles is a japanese noble recluse, and Erik is a tengu, attracted by a gift left in compassion).

"The Attempt", Charles notices, that Erik loves him not only platonically, and though he completely stright, he decides to try and give Erik something good in his life, the reason to dare to hope. But good intentions and love, or not, going against his sexuality prooves not that easy. In a nutshell this is a story I needed for that fandom. And it is good, though somewhat vague and not totally explained. But Charles does try.
archiveofourown.org/works/292763#main

"Enigma", a rare T-rated fic I decided to read, because of the description. This time it`s Erik, who goes back in time to fix things, because old Charles dies of illness before he could say goodbye. But the catch is that the mutant, performing the transfer, says every one of her clients said, that they got what they wanted, but lost the thing they most loved. Also the point in time is chosen by her gift, not someone`s will. And Erik finds himself as a child in from of the gates of the concentration camp? but with memories and power of his older self. And he has to live.
A moderately imaginative plot, it was a fun and enthralling read. With idea, however weak. The strong point is that the thing the old Magneto loved most and had to loose, was his anger, the driving force of his original self. And he had his parents for awhile. But the weak point is Charles died in his early 40-ties, and Erik had to live the rest of his life without him. And being offered the chance to relive his life again, he chooses to leave well enough alone, because Charles died being who he chose to be, and nothing Erik could do would protect Charles from that. And Erik decided to respect that.
It was a very inspiringly wise read, though a heartbreaking one. How am I always missing a MCD warning? HOOOOW?
Need to read more of this author, just WATCH THE WARNINGS. I`d still read it, just would be prepared to relive death as well.
archiveofourown.org/works/269859

"Father Charles", absolutely amazing four story arc. An AU, where Charles is a young priest and Erik works with the Immigrant Help. Absolutely the most thought through and wisest of the Priest-AUs. Everyone has their abilities, just less pronounced and it takes time to develop those. The story is amazing. A bit on the angst-fetish side, but it is too good to be spoiled by that. I`d prefer it more explicit. As it is, it`s more on R side, with just one truly graphic scene in the last story, closer to the end. LOved it!!
archiveofourown.org/series/15605