Grail

Description
Summon a grail with 1 HP. If the grail survives for 4 seconds, Heal 50 HP and gain 10 Money. Grail is Consumed on cast.

Strategy and Synergy
Grail is an excellent card early in a run, as you will have many fights against foes that cannot destroy it.

The healing it provides allows you to survive more, spend more health at the Dark Shop, and access Dark Worlds more consistently. The additional money also allows for more upgrades, shop restocks, and so on.

Trivia
Grail provides health and money to the player, similar to how the Holy Grail is said to provide eternal youth and infinite abundance.