The mere concept of the Perfect Run. Ryan has godlike power, he is technically the only real person in the world. So what does he do? He repeats time over and over again until a city is saved, vastly improved by his actions, and then he moves on to the next one, with no one knowing how much he helped.
Book 2:
Ryan's habit of looking for the silver lining allows him not only to find the good in a sapient puddle of ooze but also genuinely befriend most of the Psychos. When he promises to find them a cure, it's no longer an idle side project, but a part of his Perfect Run.
Livia convinces Ryan to bring back more minds with him so that he can finally no longer be alone in his immortality.
Book 3:
Ryan's first date with Livia, where he takes her to a "thin spot" between realities.
Ryan and Livia's first time.
Felix reconciling with his sisters. Even if it required them witnessing their parents try to murder him, it forges a very strong bond between all three of them.
