Sentinel
When Played: You may return a friendly non-leader ground unit to its owner's hand. If you do, draw a card.

Sentinel (Units in this arena can't attack your non-Sentinel units or your base.)

When Played: You may return a friendly non-leader ground unit to its owner's hand. If you do, draw a card.

Rules Clarifications:

• Abilities that return a card to hand must choose a card in play unless otherwise specified.