Umbra Stalker

Most creatures with a variable body read the battlefield or your hand; this one reads your discard pile, counting the black pips on every card already sitting in your graveyard. That inverts the usual relationship between a threat and the deck around it: the more mono-black, symbol-saturated spells you have already cast and dumped, the larger it arrives. A double-pipped removal spell is worth two to the tally, a triple-pipped finisher worth three, and a bin stuffed with them turns a fixed seven-mana investment into an open-ended one. The design wager is that a heavy mono-black deck fills its yard with exactly the cards that swell this, so the payoff scales with a commitment you would have made regardless rather than asking for a dedicated enabler. The vulnerability is the same as the engine: the count lives in the graveyard, so any exile effect aimed at your bin shrinks the body in real time, and it can hit the table as a 0/0 if your yard is empty or clogged with colorless and off-color symbols. The chroma mechanic always rewarded color discipline over raw mana spent, but most chroma cards measured a snapshot of the present; this is the rare one whose power line is a running ledger of how mono-black your deck has actually been playing.