Even though it's most assuredly a suicide mission, Optimus Primal still volunteers to stay with Apelinq to fight Scourge.
Noah chides Kris for hiding the fact that the pain has come back, reminding them that they’re family and they’re in this together.
Noah: We fighting this together or not at all? Kris: (Firmly) Together.
Mirage throughout the film is flippant and very casual with Optimus, making you think he doesn't respect or care about the leader of the Autobots, but when he and Noah are talking and Noah admits he doesn't think highly of how Prime acts, Mirage immediately jumps to Optimus's defense, telling Noah that Optimus is dealing with a lot of guilt and pain, showing that however he acts, his loyalty is always to Prime.
Before the climax, Optimus Prime and Noah have a heart-to-heart where the former apologizes for his previous actions, admitting that he was ultimately acting selfish and lost sight of his own ideals. However, Noah, who wasn't exactly so innocent, doesn't blame him at all and even apologizes to Prime, because the two of them were simply trying to protect their people, before realizing they should've been working as one - Autobots, Maximals, and humans.
Optimus Prime: I am sorry, Noah. Noah: You were looking out for your own. I can't even be angry at you for that. Optimus Prime: On my homeworld, we believed that the battle with darkness would continue 'til all are one. I lost sight of that. You fought for yours, as I fought for mine, when we should have been fighting the darkness together. Noah: Well I ain't done fighting yet.
Their friendship is later solidified when Optimus after destroying the portal is in danger of being sucked in only to be saved by Noah who came back for him. When Prime tells him to save himself, Noah responds with a Call-Back:
Noah: 'Til all are one!
Earlier, Elena notes that he and Noah are not so different, seeing them as big brothers in their own right, each trying to protect their families.
The fact that Mirage merged Kris' walkie-talkie into his body and has been talking with him the entire time, sharing updates and call signs with him.
Even better, it's established that Kris and Noah when talking over the radio give each other callsign (Sonic and Tails respectively) When Kris contacts Mirage again after he was seemingly fatally injured protecting Noah. It's revealed that he had given Mirage the call sign Knuckles. Showing how far the two bonded.
Earlier before Noah sets out with the Autobots, Kris tells Mirage to watch out for his older brother and Mirage gives him his word. It's one of the few times Mirage isn't joking and is completely sincere. He later successfully keeps that promise.
While Optimus remains distrustful and cynical towards the humans, Bumblebee tries to defend them and says they were nice to him, showing that even after all this time, he still regards Charlie as a friend.
Optimus never dismisses what Charlie did, seeing her more as the exception to the rule.
Primal returning to help save Optimus, doing what he couldn't in the prologue and saving a fellow commander.
The utter relief in Optimus' voice when Bumblebee returns to the battlefield.
When Primal shows that he isn't pleased that Optimus isn't the leader he expected, Airazor is quick to defend him, pointing out that Optimus merely is suffering through losses.
When Prime announces his intent to sacrifice himself to stop Unicron from coming to Earth, Primal somberly acknowledges him by saying "your sacrifice becomes our oath". Not only does he pay tribute to his fallen friend Airazor, who said the same thing about Apelinq; he is finally recognizing Optimus as the hero he had heard legends about, putting him on the same pedestal as the late Apelinq because of his intended sacrifice.
Elena is shown to have taken full credit for finding the Inca temple the Maximals hid under Peru, gaining the recognition she sorely deserved.
At the end of the movie, the G.I. Joe recruiter tells Noah they will cover Kris's medical treatment while also getting the best doctors possible. Forever. Even if he doesn't join them, it is implied that he's in.
This act of utter kindness also serves to establish the one main thing G.I Joe and the Autbots have in common: They both seek to do good.
Also when it’s made clear the recruiter knows what Noah was doing in his brief "international work", he refuses to sell out the Autobots, which the recruiter respects, further showing Noah’s loyalty to his new friends.
Despite how many times the Autobots and the Joes have fought against each other in the comics, this time it appears that the Joes are 100% accepting of the Autobots and want to fight at their side.
Just likemost ofthe filmsin theseries, Optimus delivers his trademark badass speech, solidifying him fully embracing humanity as the Autobots' newly-made ally:
Optimus Prime: I am Optimus Prime, leader of the Autobots. We have lost the Transwarp Key, and with it our ability to go home. But we have gained an ally in our battle against the forces of evil. Forces too powerful for any of us to defeat on our own. But together, we might just have a chance.
Later while returning home via Stratosphere, Optimus gives Noah a noticeable smile.
And as a first for the film series, Noah gives his own:
Noah: I am Noah Diaz. What is there to know about me? I was raised out in Brooklyn. I got a little bro who calls me Sonic, and if I gotta help save the universe in order to help save the people I love, well then that's what I'm gonna do.
A mid-credits stinger shows Noah refurbishing a junked car with a very notable silver paint job with a blue stripe, while Reek gave poor excuses for bailing on him. As Reek snarks that the car probably won't even start, Noah reveals Mirage survived, both Noah and Mirage getting revenge on Reek.
