Mystic Bayou

Soulbound (You may pair this land with another unpaired land when either enters. They remain paired for as long as you control both of them.)
{t}, Add {c}
{t}, Add {b}. Activate only if Mystic Bayou is paired
to another land.
{1},{t}, You may tap an untapped land paired to this permanent. If you do, mill cards equal to the greatest power among colorless creatures you control.