Field Spell
When this card is activated: Set 1 “Drone Sentinel” Trap from your Deck, and if you do, add 1 “Drone Sentinel” Spell from your Deck to your hand. All face-up “Drone Sentinel” cards you control gain 1 additional Sentinel Counter when they would gain counters. Once per turn: You can remove 2 Sentinel Counters from your field; draw 1 card, or instead add 1 “Drone Sentinel” card from your Deck to your hand. Face-up Spell/Trap Cards you control cannot be targeted or destroyed by card effects, once per turn.