Well I approve of the idea. Would be nice to have an alternative use to the Foul meter. Also not sure if it's been suggested but I feel like if we did get a raise function it could also come with a 2min zombie effect or something that inflicts DoT. This might be unremovable or it might be removable via Esuna. Either way it would feel like something you don't want to use too often because you're either getting a form of poison/zombie or forcing the healer to use esuna and waste time healing/DpSing. It would also mean you can limit the amount of casts as it would have a 30sec cooldown (waiting on the Foul meter) but also make you think twice about 2 well times foul meter charges. Time it right you could raise twice in a matter of seconds but would you want to?
I like the idea. If not the DoT how about a BLM raise reducing max HP for a period or something. Large Dmg Down buff applied. Something to limit it I suppose.