Rules of the Depths (U)

[Set] (This card remains on the field.) During your attack phase, when a monster on your opponent's field attacks and deals damage to your opponent, put the top card from your deck into your gauge, you gain 1 life, draw a card, and deal 1 damage to your opponent! This ability only activates once per turn. You may only [Set] one "Rules of the Depths" on your field.