Sudden Substitution

Aug 23, 2019 · If the target spell or the target creature is an illegal target as Sudden Substitution resolves, the exchange won't happen. If both targets are legal but are both controlled by the same player, the exchange won't happen.

Aug 23, 2019 · If a permanent spell is exchanged this way, its new controller will control the permanent it becomes.

Aug 23, 2019 · A mana ability is an ability that produces mana, not an ability that costs mana.

Aug 23, 2019 · In a multiplayer game, if the controller of one of the objects leaves the game after Sudden Substitution resolves, the effect that gave them control of the spell or permanent expires. If the spell is still on the stack, the player who gains control of it this way can't choose new targets for it.

Aug 23, 2019 · If the exchange doesn't happen but the spell is still a legal target, its controller may choose new targets for it.

Aug 23, 2019 · The exchange lasts indefinitely. It doesn't expire for the spell if the creature changes zones or leaves the game, or vice versa.

Aug 23, 2019 · The noncreature spell is still on the stack after exchanging control, and the creature is still on the battlefield.

Mar 19, 2021 · After a spell with split second resolves (or otherwise leaves the stack), players may again cast spells and activate abilities before the next object on the stack resolves.

Mar 19, 2021 · Players still get priority while a card with split second is on the stack; their options are just limited to mana abilities and certain special actions.