Would you use it?
Keep in mind it would be pure elemental, so neutral damage would stay exactly the same as now, and effective damage would be exactly the same as flourish. No other changes other than removing the undead bonuns and just straight up making it a pure elemental weapon. Wouldn't it still be underpowered compared to Brandish?
Because Brandishes inflict statuses. Statuses which totally change the way you use the weapons.