To proliferate means to choose any number of permanents and/or players that have a counter, then give each one additional counter of each kind that permanent or player already has
One said he could if he had two mana, so I Snapped his Birgi and untapped two of his lands, which let him use Tainted Pact to find Force of Will, incidentally exiling many important cards from his deck, and getting another card out of his hand to stop the other player from winning, which, in that spot, was far better for me than if Id been able to counter the Underworld Breach myself
A digital version called Through the Omenpaths is available on MTG Arena and MTGO starting September 23, 2025
Summon beloved Kithkin, boggarts, merrow, and Elves, that feature new and returning mechanics as well as art from new and returning Lorwyn artists