Embereth Paladin

A 4/1 with haste for four mana is a rate red has always been able to buy, but the adamant clause turns your manabase itself into the payoff: commit three red mana to the cast and the body arrives as a 5/2, still swinging the turn it lands. That is the entire bargain. Adamant asks nothing but color discipline, no cards discarded, no life paid, no permanents tapped, just the willingness to run few enough off-color sources that three red pips are reliable. The reward scales with the deck's commitment rather than the game state, which makes this a creature that reads its own manabase instead of the board. The base 4/1 line keeps the trade real: haste means it wants to attack the moment it lands, and a single point of toughness means anything that pings it back trades up, so the counter is not cosmetic. Without it, the paladin dies to incidental one-damage effects; with it, it survives to keep pressuring. As a mechanic, adamant is a low-friction way to reward a design goal Wizards has chased in many forms: making a deck pay for its own consistency. Here the payment is invisible until it isn't, and the paladin is the cleanest common-slot expression of the deal.