Hellkite Overlord

Eight mana and three colors buy an 8/8 with every relevant combat keyword stapled on, and then the design keeps spending: a firebreathing line in red to push damage past whatever can block, and a regeneration cost split between black and green that makes the body genuinely difficult to remove through combat or burn. That second ability is the one that defines what kind of finisher this is. Plenty of fat dragons close games by being big and evasive; this one closes them by refusing to die, soaking removal and trading up while the firebreathing turns an open board into a one-swing kill. The cost is the honest part: you are paying full freight for a Dragon that wants surplus mana every turn, both to grow and to survive, which means it earns its keep only in a deck already flooded with colored mana and a clock to back it up. As the payoff sitting at the top of the Jund curve (the shard wedded to black, red, and green), it reads less like a flexible threat and more like the reward for building specifically to cast it: black's resilience, red's reach, and green's mana to feed both activated outlets at once. The keyword pile and the two activations are not subtle. The dragon is what you get for committing fully to that shard of mana and the engine to run it.