This is one of those spells where I'm unsure how to fix/make better. The fervor granted was nice at one point when we had the overcap to complement it, but maybe now we should change it to be fervor overcap? Or add in an overcap line to make the buff worthwhile?
I do think changing the Potency decrease to be a % decrease is a decent start, but like you said maybe a different stat should be used as we have a pot decrease on Descant already (not that multiple debuffs is a bad thing, a la cmit debuffs /shrug).
I also think the extra buff granted via the Soul Sonata AA in the prestige tree, Demoralizing Sonata, could be increased by 10x as well with the high primary and skill stat numbers we're currently at in end game. Extra 20k in primary stats and 500 combat skills for 1min doesn't seem too unreasonable imo
