Syrithus, Apex of Change

Mutate {3}{b/g}{b/r}{r/g}
Menace, haste
Whenever this creature mutates, each opponent sacrifices a nonbasic land and loses 2 life. Put a +1/+1 counter on this creature for each land sacrificed this way. Each opponent may search their library for a basic land card and put it onto the battlefield tapped. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles it.