Barbarian Lunatic

Three mana for a 2/1 body, then three more mana plus the body itself to fire off two damage at one creature: six total mana and a dead Barbarian to answer a single threat, and the math is the whole problem with the design. The sacrifice clause sits inside the activation cost, so this is a one-shot by construction; you pay nearly half a turn's mana to consume the very creature doing the consuming. What the rate actually buys is a standing threat. An opponent who develops into open red mana has to weigh whether the 2/1 staring them down is about to trade up, and that deterrence is real even when the trade never happens, since two damage clears a meaningful slice of the early board. The ceiling is the toughness line it can reach: two damage answers a 2/2 or a 3/2 cleanly but bounces off anything with three toughness, leaving you having burned both the creature and the mana for nothing. The honest justification for a body this expensive is the graveyard-matters context these self-sacrificing creatures were built for, where a Barbarian that feeds its own death powers an engine even when the removal mode is a poor exchange. Strip that lineage away and it asks for too much setup to deliver a small, conditional shock that most decks could buy more cheaply elsewhere.