- Mystique continues to save mutants from human abuse at the beginning. Moreover, she has become a heroine and inspiring example for the mutant world for what she did in Washington in 1973. In particular, we see her rescue poor Nightcrawler (who is her son in the comics) from being forced into cage fights.
- Erik has started a family in Poland. At one point, he tells his daughter Nina that his parents (who died in The Holocaust) are still in his heart, and sings a song to his daughter as she goes to sleep.
- Nina is a mutant who can communicate with animals, and she is very much a Friend to All Living Things, bonding with forest animals that would normally flee human presence.
- A lot of Erik's life in Poland is retroactively heartwarming. Since everything that transpired in the previous film, Erik has finally decided to give Charles' way of thinking a chance. He's living among humans and has a family, and he is happy. He even saves a co-worker from death in a workplace accident by using his powers which ends up exposing him to the authorities.
- And none of this happened in the original timeline. Nina only exists because Wolverine went back in time.
- Charles had kept his word to Logan and reopened the school to welcome mutants after the 1973 events. After being so depressed in X-Men: Days of Future Past, it's wonderful that Xavier has regained most of his "joie de vivre" from X-Men: First Class, and is genuinely happy again.
- Alex brings his young brother Scott to Xavier's school once his Eye Beams powers appear. It's nice to see Charles and Alex warmly hug each other when they meet. Havok was Professor X's student for only about a year before he was drafted to The Vietnam War, and he lived his own life afterwards, but Alex is still very appreciative of the guidance that Xavier gave to him when he was a teen.
- Alex and Hank cheerily greet each other when the former arrives at the school; it's touching when one remembers how antagonistic Havok was to Hank in X-Men: First Class.
- When Scott demonstrates his power to Charles, he burns off a giant tree, doing so much damage that it splits in half. This is followed by Charles saying that is an ancient heirloom of his family. Just when he thinks that Charles is going to kick him out, Charles does the opposite and immediately accepts Scott into his school.
- Charles comforting Jean about her nightmare of the end of the world. He also receives that premonition thanks to coming in contact with Jean, and it frightens him, but he manages to overcome his apprehension so that he can calm down the much-younger Jean from breaking down.
- The moment when viewers understand that they're Birds of a Feather because of their shared telepathy.Jean: (upset) You don't know what it's like to be afraid to shut your eyes, to be trapped inside your own head.
Charles: Oh, I think I do. It wasn't so long ago that I was plagued by voices myself. All their suffering, all their pain, their secrets.
- And later, his reassurance is very touching.Charles: (caresses Jean's forehead and speaks in a soothing voice) Everyone fears that which they do not understand. You will learn to control your powers, and when you do, you will have nothing to fear.
- The moment when viewers understand that they're Birds of a Feather because of their shared telepathy.
- Alex accompanies Charles to the CIA building the next morning as both a friend and a protector. Havok isn't obligated to stay after he drops off his brother at the school, but being at the mansion again most likely triggered some nostalgic feelings in him, and Alex decides that he would like to spend some quality time with his former teacher. He even feels comfortable enough to tease Xavier about the latter's Power Perversion Potential.
- Ororo Munroe seems to be the respected leader and Team Mom of the street rats of Cairo. Look at her brief interaction with the kids; when she comes into their hideout with Apocalypse and tells them to leave, they obey instantly. Just to drive the interaction further, there's no indication that the kids are mutants; they may very well be humans, and yet they respect Ororo just fine. Fitting, considering how she will eventually become the Team Mom of the X-Men as Storm.
- We see the beginning of Scott and Jean's relationship develop. Although they bump heads at first, they quickly grow fond of one-another as they realize they both share an inability to fully control their powers, which makes their classmates scared of both of them and makes them feel at least some shame over their struggles. When Scott loses his brother, Jean also becomes the one to support and console him, encouraging him not to blame himself.
- Hank and Scott's interactions in the film; Hank is introduced showcasing how him and Alex are old friends from their time as Charles' students 20 years ago, and Hank ends up being one of the first to introduce Scott to the school. He goes out of his way to design a means to help the young man see without vaporizing everything, and during the final battle, the two are constantly by each other's side. Given their mutual connection to Alex, it appears that Hank is both going out of his way to take care of his friend's younger brother and making sure the lad's safe after Alex's death.
- When Raven hears that Erik just lost his new-found family, she rushes to Charles as fast as she can. Not because 'some humans have hurt Magneto again, we need to protect the world from his retaliation.' But because 'Erik's in trouble.'
- Hank is practically giddy when Raven returns to the school, and when he shows off Cerebro, he mentions that he based the color off of... Then he trails off, looking at Raven. She cracks a warm, appreciative smile.
- Apocalypse brings Erik to Auschwitz, and the latter calls him on why he didn't save his people if he is an all powerful God and all. It's heartwarming in a twisted way since Apocalypse is actually a Bad Boss, but he is able to sound sincere when he apologizes that he "was not there for you then, my child." Apocalypse is a villain, but it just sounds so damn comforting for him to apologize for something on the level of the Holocaust.
- Scott and Kurt take a quick liking to one another (perhaps as a Shout-Out to X-Men: Evolution), but considering their mutual status as outsiders, it's likely this is the first time either of them has had real friends.
- When Kurt asks what a mall is, Scott insists they all have to go to one now because "It's a matter of national pride". The scenes of the kids all running around the mall and joyriding together is a sight to behold. It cements the beginnings of the team's friendship perfectly.
- A minor one, but when Jean, Scott, Jubilee, and Kurt go to the mall to see Return of the Jedi, they don't make any effort to cover up Kurt's fur or tail. They don't even bother with a hood. Despite Raven's complaints about racism still being present, the fact that Nightcrawler can go out in public without inciting a riot is a huge step forward. Compare the Evolution cartoon series where he had to use a holographic watch to hide himself.
- Charles uses Cerebro in order to track Magneto so that he can offer his old friend his condolences after his family died.
- Raven's desperate "CHARLES!!" when Magneto kidnaps Charles for Apocalypse's plans. Because, even if it's been almost a decade since they last met, Charles Xavier will always be Raven's big brother.
- Kurt is shown praying for Alex's soul when he, Scott, and Jean are trapped on Stryker's plane. Kurt never even met Alex, but he was his friend's brother, so he asks God to watch over him.
- Jean giving Wolverine part of his memories back, which stops his bloody rampage throughout Stryker's compound. Not to mention her refusal to see him as an "animal" (which Cyclops prefers). Jean is truly the Junior Counterpart of her father figure Charles.
- Mystique has never forgotten her mutant friends she made back when she thought that only she and Charles were different. Havok, Banshee, Darwin, Angel Salvadore, all of whom have died... she fondly recounts their contributions into creating an organization for mutants in front of Cyclops, Jean, Nightcrawler and Quicksilver.
- This is especially meaningful for Cyclops, whose brother is Havok, who died while attempting to rescue Charles from being kidnapped earlier. Mystique specifically starts recounting the old X-Men's contributions from Havok first.
- Quicksilver participates in the X-Men's mission to reach Magneto not to apprehend him, not to stop him, but to tell him that he's his son, and that he still has a family with him and his mother. While he decides to postpone telling this, he does give hints to Erik during the fight against Apocalypse.Magneto: And why are you doing this?Quicksilver: I'm... I'm here for my family, too.
- Erik's Happy Flashback of his friendship with Charles back in 1962, which causes him to have a Heel Realization. It's clear from the way the clips from X-Men: First Class were edited, plus the soft, ethereal music playing in the background, that he still adores his old friend. Although Magneto had convinced himself there was no longer a shred of humanity left inside of him after the death of his wife and daughter, Mystique's plea that he does have a chance to save his family this time—Charles, whom he loves like a brother—makes Erik realize that he will lose someone very precious to him if he continues on Apocalypse's path of global destruction.
- Storm's Heel Realization comes when Raven sacrifices herself to save Quicksilver. Storm had been one of Raven's many admirers and seeing her hero in the same battle was enough to make her realize she was fighting for the wrong mutant. She joins the X-Men in trying to stop Apocalypse.
- Erik doing a HeelFace Turn against Apocalypse. Then when the latter catches him trying to prevent him from reaching Charles, this exchange follows:
- How does Erik announce this? He throws two metal beams in Apocalypse's path; one after the other in the shape of an X. That's when the audience remembers, Erik is a co-founder of the X-Men.
- As he is being mentally crushed in their Battle in the Center of the Mind, Charles reminds Apocalypse that he is alone and he [Charles] is NOT. Then Jean Grey enters the fray alongside John Ottman's soaring music.
- Charles gives the happy memories he had with Moira back to her, as he had erased them from her mind twenty-one years before.
- What's more is that it's clear Charles is afraid of her reaction, thinking she'll be furious with him. She merely smiles and sheds Tears of Joy, happy to have her memories back at last.
- The loyalty and devotion the young mutants display towards Charles is quite touching. This man welcomed them into his school no questions asked, and even though some of them barely know him, they don't hesitate in endangering their own lives to save him, even when some of whom haven't even had any training lessons at that point.
- Mystique told Storm about Quicksilver's dad. Usually, Mystique can't stand people who see her as a hero, but she clearly has taken a liking to the girl who was until just lately trying to kill them.
- Erik and Jean rebuild the school with their powers.
- Near the end, Erik and Charles part on good terms.Charles: You're sure I can't convince you to stay?
Erik: You're psychic, Charles. You can convince me to do anything.
Charles: Goodbye, old friend.
Erik: Good luck, Professor.
- Mystique becomes an inspiring battle trainer for the X-Men. During her speech, the camera briefly cuts to Professor X, and you can tell from his expression that he is so proud of his foster sister.
- And just like the case of the existence of Magneto's daughter, none of this happened in the original timeline, in which Mystique became a cold-blooded killer and Magneto remained the way he used to be. Wolverine's actions in the last movie changed those that would've have been his enemies for the better.
- As a Call-Back to X-Men: Days of Future Past, Xavier incorporates some of Logan's speech into his own when he suggests to Raven that she be the X-Men's combat instructor.Charles: This place needs to be more than a school. I need to be more than a teacher. I have to train these children to use their powers to use their powers to fight, for themselves and others.
Raven: I truly wish you the best of luck with that, Charles.
Charles: I don't need luck, I need you. I need your help, Raven. They need you. Storm. Scott. Jean. There are so many of us.
- An extended version of the mall scene. This time it's abundantly clear that no one is scared or creeped out by Kurt: one kid who sees him playing another game with his tail calls him "Rad" and a group of people cheer for him when he dances.