Replace Moogle Suit with Shadow Suit

Well, the RAM value to check is $11C9,Y. You want to compare it against #$9F, which is the item ID of the moogle suit.

Hypothetically this comparison would be made the same way that we check if the character is a moogle. But there's a problem...

Y is being incremented by steps of 40. But the ram block that contains $11C9 goes up by counts of 37. So if you check it in the same place and same manner as I checked for Imp, the check will fail for everyone except Actor Index $00 (Terra). I don't know how to set up another running counter to do indexed loads like that. I suppose that's what scratchpad RAM is for, but I've yet to have a success with that. I guess it would be something along the lines of "Load Scratch A, Push X, Transfer A into X, Load <value> relative to X, store in DIFFERENT scratch value, Load Scratch A again, Add <37> with Carry, Store Scratch A, pull X, and load the second scratch with our result", but again, I've yet to have success with techniques like that.