FirebendingFirebending is a triggered ability. “Firebending N” means “Whenever this creature attacks, add N . Until end of combat, you don’t lose this mana as steps and phases end.”
An ability that triggers whenever a player firebends triggers whenever a firebending ability they control resolves. (CR 702.189) 1 (Whenever this creature attacks, add
. This mana lasts until end of combat.)
TapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) an untapped Ally you control:
ExileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) target card from a graveyard.
Whenever this creature attacks, 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) an Ally spell from among cards you own exiled with this creature.