EX Special Attacks and Chain Attacks reduce the target's DEF by 30% for 2s. This effect does not stack.
The Vault is a W-Engine in Zenless Zone Zero. One W-Engine can be equipped by each agent.
W-Engines increase the Base ATK of the agent by a certain amount, which is determined by the W-Engine's upgrade level.
The Vault has a secondary effect which increases an agent's ATK.