FlashFlash is a static ability that functions in any zone from which you could play the card it’s on. “Flash” means “You may play this card any time you could cast an instant.”
Multiple instances of flash on the same object are redundant. (CR 702.8)
This spell costs
less to
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) for each instant and sorcery card in your graveyard.
This creature enters tapped if it's not your turn.
When this creature enters,
tapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) up to two target creatures.