Goremand
Creature — Demon
As an additional cost to cast this spell, sacrifice a creature.
Flying
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When this creature enters, each opponent sacrifices a creature.
Igor Kieryluk
Core Set 2021 (M21)
• #101Rulings
As Goremand's triggered ability resolves, first the next opponent in turn order (or, if it's an opponent's turn, the opponent whose turn it is) chooses a creature they control, then each other opponent in turn order does the same knowing the choices made before them. Then all the chosen creatures are sacrificed at the same time.
(wotc • 2020-06-23)
Rulings
As Goremand's triggered ability resolves, first the next opponent in turn order (or, if it's an opponent's turn, the opponent whose turn it is) chooses a creature they control, then each other opponent in turn order does the same knowing the choices made before them. Then all the chosen creatures are sacrificed at the same time.
(wotc • 2020-06-23)