Harvest Pyre

Burn that scales with the size of your own graveyard is a different animal from burn that scales with your mana. The damage here costs no extra mana to grow: two mana buys the spell, and the variable is paid entirely in cards exiled from the bin, which makes this an answer that gets more lethal the longer a game runs and the more you have already spent. In a deck that fills its graveyard fast (cheap spells, self-mill, fetch effects), a late cast can put down almost any creature for a fixed two mana, while early it does little. The exile clause is what keeps the rate fair: every point of damage permanently subtracts a card from your graveyard, so it competes directly with flashback, threshold, and any other mechanic that wants those cards still sitting there. You are not refilling anything; you are draining one stockpile to power a single shot, and what you burn is gone. The targeting is locked to creatures, too, so this is never reach to the face or a way to close a game from across the table: it is a graveyard-powered creature answer, full stop. The design echoes delve: cards in the bin as a second currency, spent down for an immediate effect, with the tension of what you give up baked into every cast.