If you make a 10% or 50% Zygarde, it will have Aura break.
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Getting Zygarde is one of the most unique, and cumbersome, ways to get a Legendary Pokémon. To get it, you need to collect Zygarde Cells within the Zygarde Cube and take them to the special caravan in Route 16. These cells will depend on what you can do. Until you have collected all the cells, you'll be able to create Zygarde at the Zygarde Restoration Center. This allows for you to put together a Zygarde. If you have 10 cells, it will create a 10% Forme Zygarde, and if you have 50 it will create a 50% Zygarde. These have Aura Break. These Pokémon can then be used to assemble or separate the Zygarde. If you separate Zygarde, the Pokémon will be lost entirely, but can be rebuilt just with different IVs and no EVs. The level increases with the progression in your game.
After you have collected all 100 cells, you'll be able to combine them more solidly into a Zygarde with the Power Construct ability. This will then allow it to change between 10% and 50% Forme using the Zygarde Cube, and turn into Complete Forme in battle. This Zygarde cannot be separated
Do note that if you trade away or release any Zygarde created, you will lose the cells forever.
In USUM,
> After capturing Zygarde 50% (With Aura Break) at the Resolution Cave, and subsequently defeating SinaUS/DexioUM at the Aether Branch with the Reassembly Unit located at Route 16,
the player will be given a Zygarde 10% (with Aura Break), and the Zygarde Cube containing 40 cells.
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Zygarde with the Ability Power Construct cannot be separated back into Cores and Cells; however, the Zygarde Cube can be used to switch a Zygarde with this Ability between its 10% and 50% Formes.
Zygarde cannot switch between Abilities using an Ability Capsule.
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