How?

The main argument for Kashimo having RCT is that after Sukuna cuts his arm, he heals it back, but his hand is shaded with hard lines (See slides 2 and 3). This is a similar case to Higuruma where he uses RCT on his arm and similar hard lines to Kashimo cover it (See slide 1).

But Whenever We See RCT Used, there’s smoke

This is true, but it’s not all the time. There are instances where RCT is used, there is no smoke. Instead the flesh just reforms (See slides 4-6) There’s many more instances of this than just Hakari and Uraume, but I’ll leave it at that for now.

MBA is Just Creating a New Arm with CE

But if that were the case, then the arm wouldn’t have those hard lines indicating flesh. It would have been a lighter color, like the rest of his body. Flesh is drawn and portrayed a certain way, like how Sukuna was getting flared in Yuji’s domain, his muscles were exposed, drawn in a similar manner to Kashimo’s arm (See slide 9).

MBA Can Reconstruct Flesh, So It’s Not RCT

Except that’s only to manifest electrical phenomena, and that by itself comes from Kashimo’s CE, and CE itself cannot regenerate body parts. It has to be reversed to make RCT (See slides 7 and 8).