If you have control over trigger abilities, and there are simultaneous triggers during a game, you'll see a screen like this: In the case above, I've just attacked with multiple units (during a Lord of the Rings Draft game)
I would still prefer building a Metal type deck, using Solgaleo Prism Star and Dusk Mane Necrozma GX, just because Dusk Mane Necrozma is guaranteed to do 220 damage per turn, and Gardevoir GX is weak to Metal type Pokemon, but if you have any high attack cost Psychic Pokemon, Lunala Prism Star is a must
When you are up against a combo deck, you basically have one of two choices: Either you race, killing the combo player faster, than he kills you (and this often means FAST)
I mean, once you already go to the trouble of putting together a toolbox, Eladamris Call gives you additional ways to capitalize on it
Pull this in your Build & Battle box and this could cause some havoc