Lullmage's Domination

Control Magic is the reference point every blue theft spell dances around, and this one's contribution is a scaling price that ties the outlay to a variable rather than a fixed number. The X in the casting cost is the same X that gates the target: you pay for exactly the mana value you want to steal, so a mana dork costs almost nothing to take while a fatty demands the full sum. That coupling is the whole tension. The reduction clause is where it gets pointed. If the creature's controller is sitting on eight or more cards in their graveyard, the spell costs less, effectively knocking three off whatever you were paying for X and leaving you with little more than the triple-blue commitment. The clause reads the target's controller, not the caster's, which means the discount is opportunistic rather than self-enabled: you are not the one filling your own yard to trigger it. The discount arrives when your opponent's own plan has stocked their graveyard: the delve pile, the dredge-style value engine, the reanimator shell that leans on a full bin. Against those it steals their payoff at a steep rebate, exactly when they have done the work. Against a linear aggro deck with an empty yard, it is a full-price sorcery-speed steal that waits its turn. The triple-blue pip is the honest tax: this asks you to build around the color, not dip into it.