Barrier Dragon, Styracolord

:Sentinel :[Choose a card from your hand, and discard it] When this unit is placed on from hand, you may pay the cost. If you do, choose up to one of your vanguards that is being attacked, and that unit cannot be hit until end of that battle. /:Engorge (When this unit attacks, you may retire one or more of your other rear-guards. If you do, it is engorged until end of turn) : 1 When this unit becomes engorged, you may pay the cost. If you do, it gets +5000 until end of turn, and at the end of that turn, return this unit to your hand.