, Pay 1 life, Sacrifice River Foundry: Search your library for a Island or Mountain card and put it onto the battlefield, then shuffle your library.
: River Foundry becomes a 2/2 blue Merfolk creature until end of turn. It's still a land.
, Pay 1 life, Sacrifice River Foundry: Search your library for a Island or Mountain card and put it onto the battlefield, then shuffle your library.
: River Foundry becomes a 2/2 blue Merfolk creature until end of turn. It's still a land.
