Currently, Piety is a wasted stat on healers since you have more than enough MP sources to get through a fight unless you die or spam raise, both of which are fairly infrequent once you're use to a fight or essentially force a wipe anyway due to enrage. As such, it'd be nice to have a dedicated "MP dump" damage spell, a spell that does marginally more damage than a basic damage spell but with terrible MP efficiency. This allows some modicum of skill expression as you can now gauge the pace of a fight and see how much you can get away with, while also making Piety less redundant by putting it in the Tenacity tier instead of just being outright garbage.

For example:

WHM: Water/Banish- 700 MP. Instant cast. Deals 350 Potency damage
SCH: Ruin II/III/IV- 700 MP. Instant cast. Deals 330 Potency damage
AST: Comet/II/III/IV- 700 MP. Instant cast. Deals 300 Potency damage.

In this example, these MP dump spells cost 300 more MP and have 50 more potency than their base counterparts at Shb tier. It's also a marginal buff to WHM and SCH who now gain access to an on-demand weave window for ogcd abilties (and yes, I know that Thin Air is now a DPS cooldown for WHM.)

AST right now is generally better and overall harder to play effectively than WHM or SCH. This change lets WHM and SCH close that gap by opening up more opportunities to play efficiently, that is, not wasting oGCD times like AST does with its Malefic window.