by SteampunkDragon on Jun 05, 2019
Mount (Whenever a creature enters the battlefield under your
control, you may have it mount a Steed you control. Mounted
creatures can't attack without their mount, and have indestructible
as long as their mount is untapped.)
Champion's Claw can only be mounted by legendary creatures.
As long as Champion's Claw is mounted, it and mounted creature have vigilance.