K'rrik, Son of Yawgmoth

Life is the currency here, spent faster than any deck can safely replace it. The Phyrexian mana in the casting cost is the smaller half of the bargain; the real engine is the static clause that, while the 2/2 sits on the battlefield, lets you pay two life for every black pip in any cost, not just spells. Activated abilities, kicker, ward taxes, anything asking for black mana can be paid in blood instead. That turns Swamps into optional and your life total into your true mana pool, precisely the runaway math that black tutors, drainers, and instant-speed lifegain were made to abuse. The +1/+1 counter per black spell is almost an afterthought next to the resource conversion, a way to grind the body into a lifelink threat once the storm turn stalls.

This is a meaningful entry in mono-black's long flirtation with paying life for power because of its totality: earlier designs converted life on a single spell or a single ability, while this hands you a standing discount on the color's entire manabase of costs, with lifelink stapled on as a pressure valve. The friction is twofold. It only ever cares about black in a cost, never generates mana on its own, and the discount evaporates the instant the 2/2 leaves play, so every cheap payment assumes both a target for removal and life worth burning. Run it hot enough and the deck kills you before the opponent does; that fragility is the whole tension.