New prediction time, I suppose (bolded = already confirmed)
Solgaleo
Lunala
Cyrus
Some sort of prism energy
An item card (most likely one that lets you search your deck for a prism card)
Ultra Necrozma (Would be a hell of a first card and would be playable for one of the same reasons as...
So that checks Lunala off the list, then. My predictions for the next 4 are as follows ~
Ultra Necrozma
Dawn Wings Necrozma
Dusk Mane Necrozma
Regular Necrozma