Hard mode

Hard mode is a game mode introduced in V1.12 that increases the difficulty of enemies.

Activation
Hard mode is activated by talking to Mah-Linda in the upper middle part of the hub. For 10 chaos gems she will activate hard mode for the next run the player does.

Gameplay changes
With hard mode active, all enemies will behave as if the player were on the third floor of their run. This means basic enemies will frequently appear as chaos variants with increased health and damage and more attacks, or as elemental variants. Council members will have more attacks available, perform more of them in a row before being vulnerable, and be vulnerable for a shorter time.

Trivia

 * Prior to V1.12, hard mode was activated by taking the as a starting relic.