Well so maybe that's why Sukuna had two extra arms, eyes and mouth, he ate his twin in the womb and maybe that's why he was an unwanted child, basically a cannibal before he was even born. Not only this, twins share cursed energy and so they are considered failure and bad luck among sorcerers. Maybe that's why Sukuna ate his twin, tso he wouldn't have been "incomplete".
Now, the doubt is about the CT, if Fuga and Shrine are separated techniques, perhaps Shrine was actually his twin's technique while Fuga was his own, or the other way around.

That's an interesting idea, I think that might just be it. It's as good an explanation as any as for why Sukuna has at least two completely different cursed techniques.

And damn, Yuji is a beast in this chapter. Black Flash after Black Flash. This should have canceled Sukuna's gains from his own Black Flashes.

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).

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.

Look at pattern (scissors and line) made by Yuji before he cut the pillar.
Also sudden narrative that "CT appearances changes based on era due to difference of understanding."

Its similar pattern as "Cut" function in Paint software, which opposite is "copy and paste" object that already touched by it.
Sukuna can use flame not because he knew Fuga is flame but because he knew the outcome of Fuga will be Fire, result of copy-paste Jogo ability. Opposite of to cut is to mix, unite or blend, after all.

Shrine being the technique of Sukuna's brother and Fuga being Sukuna's own technique just makes far more sense.

Anyway, I'm glad he finally lost his composure for the first time in the entire series. His smugness was really getting on my nerves.

What was Kenjaku's plan for Yuji anyway? Did he want to create the perfect body for himself, one that surpasses even Sukuna?

The pattern Yuji makes when he uses Cleave is like Sukuna said, down to his interpretation of the technique. Before, Cleave and Dismantle were likened to kitchen knives because that's probably how Sukuna imagines slicing things. Yuji imagines cutting stuff with scissors

Explanation about RCT and how Yuji gain new techniques in short times.

Sukuna able to use Shrine after his own consecutive Black Flash.

Fuga (Release!) 'full name' is Kamino: Fuga (Kamino (divine gift) used kanji for stove instead, so something of: Divine Gift - Stove, Release!).

Further confirmation Shrine is a kitchen set. Not sure how it will translated to Itadori's.

I really hate what binding vows have become. Unlike vows in HxH which are risky and very often completely change the way characters are fighting, here characters (or maybe just Sukuna) are far too liberal with them and pretty much never become limitation.

So Ui Ui was the reason why Yuji swapped his soul with Kusakabe while he was training, he can teleport even just the souls of the target. And Yuji used this method twice, one with Kusakabe and the other it seems it's not revealed yet. If it's truly still untold, then it means that it will be very important for the next part of the fight.
Now Sukuna had to use binding vows to perform his domain even if not exactly as his usual ones due to his conditions (he only has two hands from the same side and very low output), but he managed to keep the range, all because Yuji's black flashes made his RCT output collapse each time he got hit. Since SUkuna is finally using Fuga, and maybe it's actually part of the Shrine but he separated it from the cutting technique to use it as an ace in the hole, then he finally has nothing more to show, especially since using binding vows for his domain will have huge drawback later, he already had to complicate a lot the use of the world cutting slash for the rest of his life to kill Gojo, who knows what complications he used to perform his DE in his conditions.
So right now the second person Yuji performed soul swapping in his training is the new "when the heck he is gonna use Fuga", now Yuji is the one who is still hiding something, Sukuna not anymore.

It's basically Younger Toguro going all out like in the livaction but this Sukuna is pissed?

Choso and Todo doing that big brother assistance. They sure are similar. No idea if any of these are dying.

Choso is dead and even "met" his brothers in the afterlife.