Xavier Sal, Infested Captain
Legendary Creature — Human Fungus Pirate
, Sacrifice another creature: Proliferate. Activate only as a sorcery. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Legal in
Legacy, Vintage, Commander
Rulings (11)
You don't have to choose every permanent or player that has a counter, only the ones you want to add another counter to. Since "any number" includes zero, you don't have to choose any permanents at all, and you don't have to choose any players at all.
2023-11-10
Players can respond to a spell or ability whose effect includes proliferating. Once that spell or ability starts to resolve, however, and its controller chooses which permanents and players will get new counters, it's too late for anyone to respond.
2023-11-10
If a player or permanent has more than one kind of counter on it, and you choose for it to get additional counters, it must get one of each kind of counter it already has. You can't have it get just one kind of counter it already has and not the others.
2023-11-10
An ability that triggers "Whenever you proliferate" triggers even if you chose no permanents or players while doing so.
2023-11-10