For my part, I'm absolutely against the immortality being explained. I think it would cheapen the narrative, whatever explanation it may be. They are immortal, that's it. It's not important WHY they have this gift, the only thing that matters is what they do with it and how it affects them.
i think a lot about how the immortals face problems that are fundamentally human. like, booker outlived his sons, andy lost purpose in her life, nile just went through a big change and cant return to an old phase of her life. very common, very human problems. tales as old as time.
like of course the reason for all of these problems is the immortality, but theyre still problems mortals face as well. and that fact humanizes them So Much. especially since when bad things happen to us Mere Mortals we dont know why they happened. if i happen to outlive my three sons, do i know why such a terrible thing happened to me specifically? no. same with the immortals. booker outlived his sons because he's immortal, but he doesn't know why hes immortal, so he doesn't know why he specifically had to outlive his sons either.
if you step back and say 'the squad became immortal because they got cursed by a witch' or some shit, then that takes the uncertainty from the equation. they now know why theyre immortal. they now know why these bad things happened to them, which makes their struggle so much less Fundamentally Human™ imo. so yeah. same.
