I'll like to see a 1 hour ability, and maybe something like this: "Damage and recast varies with TP ". An 1 hour ability that consume 1/2 of your current TP. More TP you have more damage and recast. With 1000 TP, it consumes 500 TP, doing full damage of the ability and a recast of 1 hour. With 500 TP, it consules 250, doing 1/2 of the damage and recast of 30 min.