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.
Improve Fate. When you or another creature within 60 feet of you succeeds on or fails a D20 Test, you can roll 2d4 and apply the total rolled as a bonus or penalty to the d20 roll. Once you use this benefit, you can’t use it again until you roll Initiative or finish a Short or Long Rest.
Seems neat with mage slayer per rest (short snd long)