Boon of Eldrich Blast, Variant (5e Epic Boon)
From D&D Wiki
Boon of Eldritch Blast
With years of researching arcane limits and your own patron you surpass the limits of this powerful cantrip. With this boon, you can cast eldritch blast as a bonus action, and you can change the damage type of eldritch blast to any one of your choice. You must choose the damage type before rolling the attack for each beam.