Power Construct

Power Construct is unique to Zygarde. When Zygarde 10% Forme or Zygarde 50% Forme falls below half HP, it changes into Zygarde Complete Forme.

As Complete Forme has a higher base HP than the other two Formes, its HP is also restored by the same amount the maximum HP increased.

Game descriptions

Sun
Moon
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.
Sword
Shield
B.Diamond
S.Pearl
Other Cells gather to aid when its HP becomes half or less. Then the Pokémon changes its form to Complete Forme.

Other languages

EnglishPower Construct
SpanishAgrupamiento
ItalianSciamefusione
Japaneseスワームチェンジ (Swarm Change)
GermanScharwandel
FrenchRassemblement