If that's all you've got, it's nowhere near enough!
"[CONT]: Sentinel (You may only have up to four cards with ""[CONT]: Sentinel"" in a deck.)
[AUTO](GC):When placed, [COST][discard a card from your hand], and one of your units cannot be hit until end of that battle.
[AUTO](VC):When placed, draw a card, and discard a card from your hand."