Bureau of Abjuration

Bureau of Abjuration enters the battlefield
tapped, unless you control a Plains.
{t}: Add {w}.
{3}{w}{w}, {t}: Prevent all combat damage that
would be dealt to and dealt by target attacking
creature you don't control.
The Abjurers keep the monsters down on Thag. Be
mindful not to do anything that makes them see you
as one.