Raging River

Whenever one or more creatures you control attack, each defending player divides all creatures without flying they control into a "left" pile and a "right" pile. Then, for each attacking creature you control, choose "left" or "right." That creature can't be blocked this combat except by creatures with flying and

creatures in a pile with the chosen label.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6ocfk38l4jpb1hsqqfzsdj.