Bandage Up
Bandage Up is a colorless uncommon 0-cost skill that heals 4 HP and Exhausts. As a free healing card, it recovers lost HP without spending energy. While 4 HP may seem modest, it's available to all characters and heals for free in combat. The Exhaust keyword means it fires once per combat, so it's more of a safety net than a sustained healing source. It's particularly useful after elites or tough encounters where you've taken unavoidable damage.
Bandage Up is best viewed as a run-economy card: each combat where you use it potentially saves a healing potion or spares HP for the next encounter. At 0 cost and 0 deck pollution (it Exhausts), it has virtually no downside beyond occupying a deck slot. It fits any deck that lacks self-healing and wants a small HP cushion. Upgraded, Bandage Up heals 6 HP instead of 4, providing 50% more healing per combat use and making the free healing considerably more meaningful against high-damage fights.