Ghoulcaller Gisa - Intelligence

Ghoulcaller Gisa turns one high-power creature into a Zombie board. The first checks are haste or untap support, a legal sacrifice target, power scaling, Zombie payoffs, recursion, and whether Thornbite Staff combo prerequisites are actually present.

Gisa's ability is an activated ability with {B}, tapping Gisa, and sacrificing another creature as activation costs.

Gisa cannot sacrifice herself because the cost says another creature.

The sacrificed creature is gone before opponents receive priority, and countering the ability does not return it.

Removing Gisa after activation does not remove the ability already on the stack.

Gisa needs haste or continuous control since the start of the turn to pay the tap cost.

X is the sacrificed creature's power, using last-known information if that creature is no longer on the battlefield.

Temporary power modifications, counters, Equipment, Auras, and continuous effects can change X before the creature is sacrificed.

A zero-power creature creates zero Zombies.

Gisa's ability does not target, so hexproof, shroud, protection, and indestructible do not stop the sacrifice cost.

A creature that cannot be sacrificed cannot pay the activation cost.

Token creatures can be sacrificed and still trigger dies abilities before ceasing to exist.

The Zombie tokens enter simultaneously; per-creature entry triggers see each Zombie and one-or-more triggers see one batch.

Panharmonicon does not interact with Gisa's activated ability.

Thornbite Staff can untap Gisa when a creature dies from the activation cost or loop sacrifices.

Newly created Zombies can be sacrificed even though they have summoning sickness.

Grave Pact and Dictate of Erebos trigger from the activation-cost sacrifice.

Rings of Brighthearth and Illusionist's Bracers copy the activated ability but need separate review for role claims.

Copied Gisa abilities do not require another sacrifice unless the copying effect requires a new activation.

Commander replacement and graveyard timing must follow current Commander rules.

Convert Rotting Regisaur, Phyrexian Dreadnought, Yargle, or boosted creatures into large Zombie batches.

Use Gisa's tokens as the Zombie density engine for lords, draw, drain, and mass recursion.

Use Gisa as a sacrifice outlet and turn Zombie bodies into drain, cards, mana, and edict pressure.

Sacrifice one large creature, recur it, and repeat the power-to-token conversion.

Use Thornbite Staff untaps, Phyrexian Altar mana, and a Zombie power boost to create a token-positive loop.