Boon of the Iron Mind
Source: Arcana Unleashed
Epic Boon Feat (Prerequisite: Level 19+)
You gain the following benefits.
Ability Score Increase. Increase one ability score of your choice by 1, to a maximum of 30.
Unshakable Focus. When you are maintaining Concentration on an effect, you lose Concentration only if you cast a spell or activate another effect that requires Concentration, if you have the Petrified or Unconscious condition, or if you die.