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
With this card on the field, once per turn, you can target one card on the field and destroy it, whilebeing able to negate an Effect when activated once per turn, and destroys the card in the process, The key to beating Tenyi Swordsoul Decks is negating & interrupting their Summons & Card Effect activations
15.8 If the conditions of clause 15.5 are satisfied and clause 15.7 does not apply, the maximum liability of the Company to a Buyer shall be the Sale Price of the relevant Lot and the Premium (if paid by the Buyer) but shall not include a refund of storage charges, insurance, interest and the like, or any consequential or indirect loss or damage suffered or expense incurred by the Buyer
Akoum Firebird: the obligatory Phoenix
Garruk has two more abilities
Cryptic Serpent's ability doesn't change its mana cost or mana value