Target creature gets +X/+0 until end of turn, where X is its power. //
AftermathAftermath is an ability found on some split cards (see rule 709, “Split Cards”). It represents three static abilities. “Aftermath” means “You may cast this half of this split card from your graveyard,” “This half of this split card can’t be cast from any zone other than a graveyard,” and “If this spell was cast from a graveyard, exile it instead of putting it anywhere else any time it would leave the stack.” (CR 702.127) (
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) this spell only from your graveyard. Then
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) it.)
Target creature gains
double strikeDouble strike is a static ability that modifies the rules for the combat damage step. (See rule 510, “Combat Damage Step.”)
If at least one attacking or blocking creature has first strike (see rule 702.7) or double strike as the combat damage step begins, the only creatures that assign combat damage in that step are those with first strike or double strike. After that step, instead of proceeding to the end of combat step, the phase gets a second combat damage step. The only creatures that assign combat damage in that step are the remaining attackers and blockers that had neither first strike nor double strike as the first combat damage step began, as well as the remaining attackers and blockers that currently have double strike. After that step, the phase proceeds to the end of combat step.
Removing double strike from a creature during the first combat damage step will stop it from assigning combat damage in the second combat damage step.
Giving double strike to a creature with first strike after it has already dealt combat damage in the first combat damage step will allow the creature to assign combat damage in the second combat damage step.
Multiple instances of double strike on the same creature are redundant. (CR 702.4) until end of turn.