Power Construct in Pokémon Ultra Sun & Ultra Moon

Other Cells gather to aid when its HP becomes half or less. Then the Pokémon changes its form to Complete Forme.

At turn end, Zygarde becomes Complete Forme at 50% HP or less.

At the end of a turn, Zygarde 10% or 50% with Power Construct becomes Complete Forme when its HP is at most 50% of maximum. Its maximum HP rises and current HP increases by the difference. It remains Complete until battle ends; restoring HP does not reverse the change.