Stronghold Overseer

Most creatures carrying the parallel-plane evasion of Shadow are cheap, single-minded beaters: a body that swings unblockable past anything grounded and ignores whatever else is happening on the ground. This 5/5 flier asks the question that arrangement leaves dangling: what happens when both players have shadow creatures, and the ghostly side battle stops being a one-sided race? Its activated ability functions as a lord with two halves. Pumping the power of every shadow creature assembles a coordinated alpha strike on the shadow front, while the simultaneous power penalty reaches across to the ordinary battlefield and softens the attackers and blockers that can never trade with shadow anyway. Because the penalty touches power and leaves toughness alone, it does not wipe a board by itself; repeated across turns, though, it can grind down the offense of a deck that wrote off the keyword. The double-black activation makes that a lever you can pull every turn, and the triple-black casting cost states plainly how deep into one color a deck must commit to run it. Shadow never accumulated a creature pool large enough to make a dedicated build more than a curiosity, which leaves this Demon as the closest the niche came to a genuine payoff: not another body shuffling along the parallel plane, but the one that bends it.