Bygone is an unlockable trinket in Community Remix, a mod for The Binding of Isaac.

Replaces one type of heart with another:
• Hearts, Scared Hearts, and Blended Hearts with Soul Hearts.
• Half Hearts with Half Soul Hearts.
• Double Hearts with Black Hearts.

Beat Insane Mode as ???.

• Check out the trinket description on the mod's external Wiki.
• Download Community Remix from the Steam Workshop.