ConvokeConvoke is a static ability that functions while the spell with convoke is on the stack. “Convoke” means “For each colored mana in this spell’s total cost, you may tap an untapped creature of that color you control rather than pay that mana. For each generic mana in this spell’s total cost, you may tap an untapped creature you control rather than pay that mana.”
The convoke ability isn’t an additional or alternative cost and applies only after the total cost of the spell with convoke is determined.
A creature tapped to pay for mana in a spell’s total cost this way is said to have “convoked” that spell.
Multiple instances of convoke on the same spell are redundant. (CR 702.51) (Your creatures can help
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. Each creature you
tapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) while casting this spell pays for
or one mana of that creature's color.)
Choose a nonland card name.
SearchTo search for a card in a zone, look at all cards in that zone (even if it’s a hidden zone) and find a card that matches the given description.
If a player is searching a hidden zone for cards with a stated quality, such as a card with a certain card type or color, that player isn’t required to find some or all of those cards even if they’re present in that zone.
If a player is instructed to search a hidden zone for cards that match an undefined quality, that player may still search that zone but can’t find any cards.
If a player is searching a hidden zone simply for a quantity of cards, such as “a card” or “three cards,” that player must find that many cards (or as many as possible, if the zone doesn’t contain enough cards).
If the effect that contains the search instruction doesn’t also contain instructions to reveal the found card(s), then they’re not revealed.
If searching a zone is replaced with searching a portion of that zone, any other instructions that refer to searching the zone still apply. Any abilities that trigger on a library being searched will trigger.
If an effect offers a player a choice to search a zone and take additional actions with the cards found, that player may choose to search even if the additional actions are illegal or impossible.
An effect may instruct a player to search a library for one or more cards more than once before instructing a player to shuffle that library. This is the same as a single instruction for that player to search that library for all those cards. The player searches that library only once.
If multiple players search at once, each of those players looks at the appropriate cards at the same time, then those players decide in APNAP order (see rule 101.4) which card to find.
If an effect instructs a player to search outside the game for a card, that player may choose an appropriate card they own from outside the game. (CR 701.23) target player's graveyard, hand, and library for any number of cards with that name and
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) them. Then that player shuffles.