Why can't 2 Necrozmas Ultra Burst in the same turn in a double battle?

I battled the GameFreak directors in HeaHea city daily, using 2 Necrozmas, one Dusk Mane and one Dawn Wings. I Ultra Bursted one of them and the other didn’t…

Please explain to me why can’t I Ultra Burst 2 Necrozmas on the same turn?

Pleaselog inorregisterto add a comment.

You can only do one Ultra burst per battle because Ultra bursts require using a Z-move, and you can only use one Z-move per battle.source

Gamefreak Programed the game to have one Z-Move Per Battle. Since you are Battling Online, Two Ultra Necrozmas would be too overly powerful as the base stat total is higher than arceus himself. So add two of them and the opposing team is doomed, Making the other person rage quit most likely because you would be playing unfairly with 2 super powerful ultra necrozmas. However, You can have two fused necrozmas, one with Dusk mane Necrozma, And one with Dawn Wings Necrozma. The maximum is two different fusions besides ultra necrozma. You cannot have more than two fusions of one kind in your game or that fusion will be stuck that way because in order to fuse another sogaleo for example if you still have a sogaleo fused with necrozma, you must first defuse the necrozma attached to sogaleo to use a different sogaleo.