Summon: Bahamut

A chapter ability doesn't trigger if a lore counter is put on a Saga that already had a number of lore counters greater than or equal to that chapter's number. For example, the third lore counter put on a Saga causes the chapter III ability to trigger, but chapters I and II won't trigger again.

The mana value of a nonmodal double-faced permanent is the mana value of its front face, no matter which face is up.

Saga creatures have two sections to their text boxes. The first section, above the type line, contains their chapter abilities, and the second section, below the type line, contains any other abilities (or italicized flavor text). Any abilities in the latter section aren't chapter abilities and apply no matter how many lore counters are on the creature.

Use the total mana value of other permanents you control as Summon: Bahamut's fourth chapter ability resolves to determine how much damage is dealt.

If a permanent you control has {X} in its mana cost, X is 0 for the purpose of determining its mana value.

Once the number of lore counters on a Saga is greater than or equal to the greatest number among its chapter abilities, the Saga's controller sacrifices it as soon as its chapter ability has left the stack, most likely by resolving or being countered. This state-based action doesn't use the stack.