[CONT]:
Sentinel
(You may only have up to four cards with "[CONT]: Sentinel" in a deck)
[AUTO]:[Choose a card from your hand, and discard it] When this unit is placed on (GC) from your hand, you may pay the cost. If you do, choose one of your vanguard that is being attacked, and that unit cannot be hit until end of that battle, and if you have a card named "Mediator, Ame-no-Sagiri" in your drop zone, choose up to one card in your damage zone, and turn it face up.