Choose the hands first
At the Ancient Bridge, Calypso joins the fight. The head has Invincibility in Numbers until every other enemy is defeated. Focus one hand down, then the other; do not spend turns testing the invulnerable head.
Read the three different wind-ups
Left Zooming begins with a slow fist movement and suddenly accelerates into the party. Right Flick tilts down slightly before the flick. The head opens its mouth and gathers an orange ball for Ray of Ra. Each listed attack deals 10 base damage; the hand attacks can apply Ankh and the ray can Burn.
Use recovery outside the Special tab
Choose healing items or an available Cure action. The head and hands are Item-Resistant, so damaging consumables are not a replacement for compatible weapon attacks. That attribute does not stop you from using an item to heal a teammate.
Mechanics references: Attributes · Cure
Pit Floor 48 changes the gate
The head needs every other enemy defeated, not only its hands. If it remains invulnerable after the hands fall, check for another living enemy on the floor. It is not a second head phase.