Bulwark

From publisher description:

Heroic Co-operative Deck-Building!

Be a hero valiantly coming to the aid of a stronghold as a vast army bears down on it! Use the resources of the stronghold and your own unique abilities to keep it from overwhelmed.

Build a deck of cards to play with as you go and do your best to defeat the foes as they appear.

Choose one of 3 heroes - Arpad of Lhun, Zsuzsa Slatewalker and Sandor the Wise - to help a besieged settlement.
Face one of 2 pre-built armies, the Goblin Horde or the Fire Lizard Crusade, or customise your own.
Set how challenging you want the defence to be.
Save Fort Briggs!

In Bulwark, players use "Heroism" to purchase cards for their hand, and play those cards to upgrade their hero and fight monsters.