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)
Split secondSplit second is a static ability that functions only while the spell with split second is on the stack. “Split second” means “As long as this spell is on the stack, players can’t cast other spells or activate abilities that aren’t mana abilities.”
Players may activate mana abilities and take special actions while a spell with split second is on the stack. Triggered abilities trigger and are put on the stack as normal while a spell with split second is on the stack.
Multiple instances of split second on the same spell are redundant. (CR 702.61) (As long as this spell is on the stack, players can't
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) spells or
activateTo activate an activated ability is to put it onto the stack and pay its costs, so that it will eventually resolve and have its effect. Only an object’s controller (or its owner, if it doesn’t have a controller) can activate its activated ability unless the object specifically says otherwise. A player may activate an ability if they have priority. See rule 602, “Activating Activated Abilities.” (CR 701.2) abilities that aren't mana abilities.)
FlyingFlying is an evasion ability.
A creature with flying can’t be blocked except by creatures with flying and/or reach. A creature with flying can block a creature with or without flying. (See rule 509, “Declare Blockers Step,” and rule 702.17, “Reach.”)
Multiple instances of flying on the same creature are redundant. (CR 702.9)
Other white creatures get +1/+1.