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.
While proliferating, if you choose a permanent or player with multiple kinds of counters, the permanent or player gets another counter of each kind, not just one kind. This change from the original proliferate rules was introduced in a previous set.
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.
Last observed on Scryfall 2 months ago at $0.22. Over the trailing 90 days the price moved between $0.03 and $0.26 across 49 observations. Cross-checked across TCGplayer, eBay sold, Cardmarket EU, and Star City.
This printing is one of 3 catalogued treatments from MH2 — the lineup includes Foil and Nonfoil alongside the standard finish. Across our catalog the Rarix library tracks every variant in the same family so collectors can compare price, scarcity and demand inside a single lineage.
Card #36 of *Modern Horizons 2*, the set that shipped alongside the June 2021 Modern Horizons 2 release.
Card type: Instant, color identity white, printed at common. Commons fill the bulk of a booster pack's volume. Mana cost: {1}{W} (2 converted). Keyword abilities: Entwine and Proliferate.
Legal in Modern, Legacy, Vintage, Commander, and Pauper.
EDHrec ranks this card #7,952 in Commander, putting it in the niche-pick tier of the format's playable pool.
Illustrated by Iain McCaig. Rarix catalogs 72 other cards credited to this artist.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Iain McCaig
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
If you cast this spell by paying its entwine cost, you will be able to proliferate the counters that you placed with the first mode.
If a permanent has +1/+1 counters and -1/-1 counters on it, they're removed in pairs as a state-based action so that the permanent has only one of those kinds of counters (or none of either kind of counters) on it.
To proliferate, you can choose any permanent that has a counter, including ones controlled by opponents, and you can choose any player who has a counter, including opponents. You can't choose cards in any zone other than the battlefield, even if they have counters on them.
