Automatic Energy Regen is increased by 0.45/sec when not in battle. When an EX Special Attack hits an enemy, Physical damage is increased by 2%, stacking up to 15 times and lasting 1s. Repeat triggers refresh the time.
Housekeeper 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.
Housekeeper has a secondary effect which increases an agent's CRIT DMG.