Requiem Monolith

The clever wrinkle is that this weaponizes an effect that reads as a gift. Handing a creature "whenever this is dealt damage, draw that many cards and lose that much life" looks like a rider bolted onto a body, a symmetric-seeming offer where the trigger's owner does the drawing and pays the life. What turns it from a curiosity into a lever is the follow-up: the artifact offers to shoot the granted creature for a single point, and if the target is your own, its controller can let the ping land, converting the grant into a one-card-for-one-life draw. Point it at your own creature and you buy a card at the cost of a life and a point of damage, so anything with enough toughness to survive the shot becomes a repeatable-across-turns source (the tap means once per turn absent an untap effect, and any noncombat damage stacked onto that creature deepens the draw). Point it at an opponent's creature and the choice inverts: their controller decides whether to eat the artifact's damage, so the pressure moves into combat, where their blocker becomes a source of cards at the cost of their own life every time it takes a hit. The sorcery-speed clause is what keeps this from being a combat trick: you install the effect on your main phase, before the turn breaks, so the draw is always a bet placed in advance rather than an instant-speed reaction. Black has long paid its own life for cards; this keeps that bargain and widens who wears the ability, reading as generosity across the table while functioning as advantage on your own side.