Return to Sender (Return 2 Sender in the beta tests) is an Advanced Powercard in Bloons Card Storm. It removes a target Bloon or Monkey from the board and returns it to the owner's hand. It can be used on either player's cards. It removes all stat changes from the target. Using it on an opponent's card while their hand is full will delete the card instead.
For Monkeys, the target loses all changes to ATK, ammo (including Temporary Ammo), delay, and additional keywords.
For Bloons, the target loses all changes to delay, Health, Armor, Shield, status effects, and additional keywords.
Outside of Adventures and Boss Battles, this card and Salvation are the only way for most cards that cannot normally be added to a deck (e.g. Baby Monkey) to be in a player's hand.
The card art depicts Adora, who was not a playable Hero until after the card was released, and uses her design from Bloons TD 6. She is angry outside at the front door of a house near a parcel; she's frowning, pointing her finger outside with her right hand, and placing her left fist on her left hip.
Return to Sender's versatility is the most powerful aspect of the card. It can fit in almost any deck because of how useful it is in almost any scenario or versus any deck archetype. It can be used to remove dangerous Bloons that are about to leak, nullify Monkeys and their buffed effects, re-play your own cards, or, if the opponent has a full hand, have all of these effects fully remove the card instead of just putting it back in their hand. Its removal effect can initiate a wincon, such as removing an enemy ARBITR or to perform certain OTK combos where a single Monkey is preventing OTK.
Aggro may use this card to stop ARBITR or to remove a slow dangerous Bloon.
This card is effective for OTK and Burn decks by being able to remove Defenders or other vital defensive monkeys like Corvus Academy of Arts.
Monkeys with On Play effects can be replayed if removed by Return to Sender. Of these Monkeys, this is best used for Bloon Master Alchemist, which in some cases is better than on a Bloon, and Thunder Druid, for another board clear.
Adora players seeking to recycle or reuse their own Monkeys can use Salvation, which is cheaper and has additional benefits, while saving Return to Sender for other uses.
If played while the opponent's hand is full, the card will not return, removing it completely like a true removal. However, this is never the case if used on the player's side, because playing Return to Sender would always give room to another card. Deleting an opponent's card is particularly impactful against long-term card wincons such as The Eternal, as well as powerful Ultra Rares like Grand Saboteur and MOAB Eliminator.
Against a Return to Sender, be careful not to buff the same Bloon or Monkey too much. For instance, with multiple of the same Monkey, split Try this! across the Monkeys, and with Bloons avoid buffing the same Bloon twice. Evading Return to Sender via delay reduction onto a Bloon to 0 (especially Quick Ready) can also work for decks equipped for this.
Return to Sender can be used to open up a slot for another friendly Monkey, or to add room for a stolen Monkey via Expert Negotiator.
Computer opponents, especially Dreadbloon, don't use Return to Sender effectively on your cards; very often, they target the most expensive Monkey or Bloon, or the lowest delay Bloon with highest Health, don't single out scalers or Unique cards, and often don't think about the possibility of the affected card being re-played.
Against Dreadbloon, Return to Sender is beneficial, limiting Dreadbloon from overbuffing individual Bloons with Health and/or Armor, stalling out a 0-delay Lead Zeppelin, or returning a valuable Monkey.