[Ka-el]

Originally Posted by Tactics

Spoiler for :

Shrine is almost certain belongs to his brother as:
- It inherited by Yuji
- Sukuna passion is to eat.

Considering Maki case of incomplete Heavenly Restriction prior to Culling Game, it's safe to assume that his brother got all the talent (DE) but weak, while he's just like Yuji (strong physical, absorb everything he eat).

Fuga likely RCT as:
- In databook it's written as part of Shrine like Cleave and Dismantle.
- Sukuna specify it's something Cursed Spirit won't be able to understand (Cursed Spirit cannot use RCT).

Spoiler:

Well Yuji inherited the Shrine by being Sukuna's vessel and it was awakened by his black flash sequence in this battle as stated by the narrator. So it could belong to either of them.

I doubt Fuga is about RCT especially because how fire is the opposite of cutting? Until now we saw that RCT applied to a CT is the mirror opposite of the CT, like Blue is pulling and Red is pushing, like RCT of Anti-Gravity is Gravity. It would make more sense if RCT of cutting was mending, for example.
Also he didn't say that a cursed spirit wouldn't understand but that a cursed spirit wouldn't know, in fact Sukuna said that he though it was known that he had flames, so probably he expected it to be recorded in some books of history and so a cursed spirit of course wouldn't know about it, especially if it's not a very ancient cursed spirit.