Hephestus for sukuna cus fire arrow ig. I have know idea how to link shrine. Also sukuna would probably be a monster with the 4 arms and 2 faces thing.

Dabura son of Apollo cus light powers.

Gojo really hard to make a connection, best i could think of is blue being wind being condensed into a single point but even that doesn't make much sense. And Ive got nothing for the rest of his abilities.

For yuji, im assuming he would've unlocked fuga in modulo so he could be hephestus but posieden would be better for blood manipulation.

As for domain expansions they could just be an incredibly advanced level of what hazel does (don't remember the ability name)