Castle Azral

Castle Azral enters the battlefield tapped unless
you control 2 or more knights or dragons.
{t}: Add {c}.
{6}{w}{b}{r}: Until end of turn, Castle Azral
becomes your choice of a 5/5 dragon with flying
or a 2/2 knight with vigilance. If you choose the
knight gain 5 life. This ability costs {1} less to
activate for each knight and dragon you control.