Interesting. I was focused on body only.
Now I am reminded of what Kenjaku said when Geto's body tried to strangle Kenjaku when Gojo called him (when he was being sealed).
He said the body was the soul and the soul the body.
I am not sure. Seems like a paradox. Like, if body can be healed with RCT, then why not soul?
I think Gege also cleverly avoided this, dont you think?
Mahito never faced someone with a RCT, right?
Clever, if Gege did it intentionally.
This makes me think about Sukuna, will he be able to heal damage to his soul via RCT? We will surely see soul based attacks in coming chapters.
If Yuji keeps on attacking Sukuna and the damage accumulates, it is game over for Sukuna.
i think it's not exactly the case.
few points:
1. mahito changes shape of junpei's soul. yuji asks sukuna to rct him and is ready to make a binding vow. but sukuna goes “lol nah go fuck yourself.” mahito says, that maybe with rct he could restore the shape of junpei's soul, but seeing that sukuna refuses to make a vow, he suggests, that sukuna cannot heal the others (but we know that he can, actually. so it can be exlpained by mahito's inexpirience with his own ct or that gege just retconned the possibility to heal with rct the effects of mahito's ct).
2. jogo feeds fingers to yuji in shibuya and asks sukuna to make a vow of full control. at the same time, he says that sukuna can heal other people, but the effect of mahito's ct specifically cannot be healed.
3. maki and yuji fight against sukuna. yuji says that sukuna is diehard and he needs to be fucked to the fullest, he won’t die anyway. maki wonders if the fact, that he can't be killed, means that he can heal the damage from her soul-cutting katana.
4. sukuna is very good at manipulating souls. he knows how to divide it into cursed objects, he's been with several souls in one body, he knows how to control the second soul in megukuna body, he wasn’t surprised at all that mahito can change souls.
5. naoya in the form of a curse healed himself from a damage, caused by maki's soul-cutting katana.
conclusion?
rct can heal the body and the soul.
otherwise, maki woudn't ask herself about possibility of sukuna to heal himself from a damage made by her katana.
there would be no words about the fact, that sukuna can heal the others, but cannot heal the effects of mahito's ct. they just cannot be healed.
naoya would not be able to heal himself from a damage made by soul-cutting kanata.
based on this and the fact, that the body is the soul and the soul is the body, it means that the rct heals both the soul and the body completely. but it cannot heal the effect of mahito's ct, this is the trick. the thing is that it doesn’t just damage the soul, but changes its shape. and rct is the opposite - it doesn’t change the shape of the soul, but just heals it from a damage.
in the end, mechamaru could not be cured by rct, but mahito could cure him, by changing his soul's form.