in its mana cost, X is 0 for the purpose of determining its mana value.Summon: Bahamut combines a large flying creature with a four-chapter Saga that removes permanents, draws cards, and eventually damages every opponent. Its first two chapters each destroy up to one nonland permanent, giving the nine-mana investment an immediate answer and another on a later turn. The third chapter draws two cards, while the final chapter turns the mana value of your other permanents into a large damage event.
Ramp decks can use Bahamut as a colorless top-end threat that affects more than creatures. Destroying an opposing engine on entry helps stabilize the board, while flying gives the body a combat role as the chapters advance. Permanent-heavy decks can also build toward a substantial final chapter because artifacts, creatures, enchantments, and other permanents with mana costs contribute to the total.
The final damage excludes Bahamut itself, so its own nine-mana value does not add to the calculation. Ordinary lands and many tokens contribute zero, which means a wide board is not necessarily a high-mana-value board. Choose the surrounding threats with that distinction in mind if the final chapter is a major part of the plan.
Blinking Bahamut can restart its Saga progression and reuse the early removal chapters, while sacrificing after the final chapter limits how long the creature normally remains. It also lacks haste, so the first turn's value comes primarily from the entry chapter. Build with enough acceleration and useful permanents that both the early interaction and the eventual damage support the same late-game plan.
