Terminal Agony

Unconditional creature removal usually pays for its lack of restrictions with an inflated tag or a bite back at the caster; the discipline here is that the four-mana sorcery-speed price gets entirely rewritten when the card is discarded rather than cast. Paid for in full, it is a slow, honest Terror at a bloated cost. Discarded, it collapses to a two-mana kill spell whose only string attached is the discard that put it in motion, and that discard was a cost you wanted to pay rather than a drawback. That is the whole design axis: the printed rate is deliberately unappealing so the madness rate is the one that matters. Black-red is the natural home because both halves of the pair traffic in discard as engine fuel: looting, rummaging, draw-and-discard of every stripe, all of which turn what would be a stranded card into removal that costs a hand slot you were emptying anyway. Madness also lets you deploy it on an opponent's turn: pitch it in response to something and it answers for a discount. The catch is structural rather than situational. It wants a shell that generates its own discard outlets to unlock the cheap side; outside one, the madness clause is inert and you are left holding a four-mana Terror that only ever wanted to be discarded.