Heirlooms Only! is a Feat in King of Cards
How to Acquire[]
This Feat can be acquired by beating any boss using only Heirlooms. Using the Shoulder Bash in a stage prior to the boss fight does not count.
Tips[]
Specter Knight fought in the Spectral Ravine is the easiest boss to beat with Heirlooms. Maxing out King Knight's health and Vigor is recommended to avoid running out of either. The Dueling Glove is also recommended for its cheap cost in Vigor per activation.