GLEASON'S PROFILE

I remember in FFXI White Mages stored "points" as they healed up to a certain maximum if they were in a specific stance. Said points made their Holy spell more powerful, but it took a while to cap it out, and the points were reset once cast.

I don't know the damage scaling of your game, but perhaps something like GRS suggested for point accumulation, and then another comment event/ variable check, in the vein of "if v > x then v = x", would let you keep that potency rolling?