Egocentrism

Description
Any damage that wasn't dealt by you will be directly dealt to you.

Effects
From the technical standpoint, any damage that is dealt to an entity which does not come from the "Player" entity or is targeted at the "Player" entity, will queue the same damage to the player. This means that any environmental damage that happens to either decorations or enemies will also happen to the player.

This makes the game more difficult by punishing the player for using the environment to his advantage.

Unlock Condition
Complete a boss fight without taking damage.

This does not require a specific difficulty, meaning that DHMIS difficulty is the best bet.

Trivia
Internally, this relic is called Relic_T_Influencer.