Hell Hammer

Once per Turn Action -

: Attack

When the combat chain closes, if you've attacked with this, banish it.

Blood Debt

Rulings

From the Dusk till Dawn release notes

Hell Hammer is considered to have attacked if its attack ability is resolved on the stack (and you went from the layer step to the attack step of combat). Targeting objects with Spectra, and closing the combat chain this way, means you are not considered to have attacked with this.

Keyword notes

Blood Debt - Blood Debt is a new keyword existing on Shadow cards. Shadow cards can inflict a loss of life to access a greater power. At the end of your turn, you lose 1{h} for each blood debt card in your banished zone.

You only lose life at the end phase. Players do not have priority during the end phase.
If you have multiple cards with blood debt, you lose 1 for each instance of blood debt at the end of turn.
Only face-up cards banished with blood debt counts and will lose you . Face-down banished cards have no effects or stats.