Idk if it was the intent, but Tom looks so much better once Cain gets onto Krakoa. He's less leafy. He's more mentally present. He starts making jokes and smiling...I genuinely think having Cain around helps him be more himself.
I'd bet it helps him feel like a person in the same way Sage had been kinda succeeding at doing before Cain got there.
He's wired into the island and a 24/7 defense that protects the spark of mutantkind.
I imagine with no one to talk to personably mixed with stress of how important his job is; he just started to become another function of Krakoa vs a living person.
Shout out to Sage tho. I think she was one of the OG Cain supporters in the 2000s (new Excalibur? Idk can't remember)
I also love how she interacts with Omega Red