Poisonous Book of Python (DRC-030 R) [Descent into the Raven's Catacombs]

"Mythic" [Reunited] "Eternal Pact with Python" - [Enter] Produce UU. Spend this will only to play water runes or activate abilities of Book entities you control. Whenever an entity is returned to your hand >>> Draw a card. This ability triggers only once per turn. [Rest],UU, discard a card: Put two [400/400] water Snake resonator tokens with [Vileborn] (2) into the field.