u/Arcane_Truth

You can use a resource-less magic action to force saving throws against being frightened, and, if it fails, use a reaction to force a different creature to make the save, but with a higher DC.

Sure, the feat is probably pumping CON (which is not ideal) since CHA is a dump stat here, but as long as you have a creature to use Devilish Aura on, you can keep juggling monsters and making them make saving throws.