FreerunningFreerunning is a static ability that functions on the stack. “Freerunning [cost]” means “You may pay [cost] rather than pay this spell’s mana cost if a player was dealt combat damage this turn by a creature that, at the time it dealt that damage, was an Assassin creature or a commander under your control.” Casting a spell for its freerunning cost follows the rules for paying alternative costs in rules 601.2b and 601.2f–h. (CR 702.173) (You may
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 for its
freerunningFreerunning is a static ability that functions on the stack. “Freerunning [cost]” means “You may pay [cost] rather than pay this spell’s mana cost if a player was dealt combat damage this turn by a creature that, at the time it dealt that damage, was an Assassin creature or a commander under your control.” Casting a spell for its freerunning cost follows the rules for paying alternative costs in rules 601.2b and 601.2f–h. (CR 702.173) cost if you dealt combat damage to a player this turn with an Assassin or
commanderA designated card for a Commander deck, governed by the command-zone, color-identity, and Commander rules. (CR 903).)
UntapTo untap a permanent, rotate it back to the upright position from a sideways position. Only tapped permanents can be untapped. (CR 701.26) all creatures you control that attacked this turn. If it's your main phase, there is an additional combat phase after this phase, followed by an additional main phase.