Darkheart Sliver

The color identity is the tell. Slivers spent most of their early life as a five-color tribe whose shared abilities pulled every creature in one direction at once, and the alternate-timeline experiment behind this design was to reissue those tribal effects in single colors and pairs the original hive never wore. Lifegain on a sacrifice outlet is the kind of effect black and green have always shared, and bolting it onto the hive turns the whole board into a stack of three-life buttons. The strategic shift is from creatures-as-attackers to creatures-as-resources: against burn or a racing aggro deck, a wide Sliver board stops being a clock and becomes a reservoir, each body cashing out for life the moment the math turns against you. The sacrifice clause does double duty, too, letting a Sliver dodge targeted removal or exile by trading itself for life before the spell resolves. The brake is built into the same line that grants the power: every activation costs you a body and whatever buffs that body was providing, so the gain is real but the board thins with each press. It is the defensive counterweight to a tribe otherwise built almost entirely around overwhelming offense.