From publisher blurb:
In a world where people’s hearts are made of stone, Agents of the mysterious organization Syn scour the world in search of Crystals, powerful relics of a bygone age.
These Agents replace their hearts with Crystals, which grant incredible powers… but also affect the bearer’s personality in unpredictable ways.
Inspired by the styles and sensibilities of anime and superhero media, the Crystal Heart setting was developed in the comic Up to Four Players as the characters were playing it. Now you too can become a Syn Agent, explore ancient ruins and hunt down powerful Crystals!
Become an Agent of Syn, replace your heart with a Crystal and gain superpowers!
(also lose your mind, but just a little)