This is valid, but its also valid to wait to pay for the spell until the final step of casting a spell: 605.3a A player may activate an activated mana ability whenever they have priority, whenever they are casting a spell or activating an ability that requires a mana payment, or whenever a rule or effect asks for a mana payment, even if its in the middle of casting or resolving a spell or activating or resolving an ability
As Mythos of Snapdax resolves, first you choose which permanents you control won't be sacrificed, then each other player in turn order does the same, knowing the choices made before them
([U/P] can be paid with either U or 2 life.) Illus
The standard version of The Wise Mothman card isn't valuable
It becomes a face-down creature spell, which means it's a colorless 2/2 and has no name or creature types
With how powerful Attack Point boosting effects have become, Injection Fairy Lily is not used often, but it's still remembered for being one of the strongest monsters of its time