[@Breo]

Apologies for the late reply. I only look over here once or twice a day at most.

Anyway, what I meant with Self Modification is that it doesn't sound right as a skill when you consider it. Self Modification is something done willingly to change your own self (like CA Hassan's Arm, or how NR does change identities, appearance, and even her mindset, depending on her Master and which fairytale is more aligned with them). Hardly it has to do with changing parts for repairs, like the thought experiment posits.

The ability to remain himself, despite any gradual changes that happen doesn't sound, or works, like Self Modification at all.

It's not a bad concept, but you probably should make it into a new skill.