Expert Negotiator is an Advanced Powercard in Bloons Card Storm. It steals a target Monkey from the opponent's side and moves it to the player's side. If the player already has all 5 monkey slots filled, then Expert Negotiator instead removes the monkey it is used on. If successfully transferred, the Monkey is always placed on the available slot closest to the bottom, and if this Monkey has On Play effects, then they trigger again. The stolen Monkey is considered owned by the stealer; using Return to Sender will return the card to their hand, but Card Backs from the original owner will be retained.
The card art depicts Agent Jericho with a briefcase full of Monkey Money (in its Bloons TD 6 design rather than its Bloons Card Storm design). He is walking on a sidewalk at a city street.
Despite being effective against inexperienced players, Expert Negotiator has many weaknesses; its expensive cost loses time to build resources, is virtually useless against aggro, and may force users to shoehorn themselves into claiming stolen Monkeys. Without the steal function, Expert Negotiator is just a Shrink that lacks a Baby Monkey for 3 extra Gold.
Competitive players often stay away from Expert Negotiator for its inflexibility, preferring other removals like Return to Sender to stop the opponent from benefiting their Monkeys while also serving additional purposes. Claiming the stolen Monkey means nothing when the opponent can just negate it with another card or an ability and gain net greater value that way.
If the opponent is currently playing aggressively, stealing a Monkey that lacks defense or ammo on the current turn is unwise. Its value diminishes heavily against decks that run cheap expendable Monkeys, and becomes completely useless against Monkeyless decks.
If your side has space, stealing Monkeys that modify other Monkeys, such as Sun Temple and Total Transformation Monkey, can be detrimental unless you can handle that.
An Expert Negotiator can counter an Expert Negotiator; this helps re-claim stolen monkeys, but heavily slows down aggression.
Note that an opponent counterplaying an Expert Negotiator may steal one of your more valuable Monkeys instead of their recently stolen Monkey.
Freeing up a Monkey space for Expert Negotiator is difficult, as filling board space is necessary to survive without much risk. Adora's Ultimate Sacrifice ability and Salvation (also exclusive to Adora) are some reliable options, while any other friendly Monkey removal that frees a space either requires more turns (i.e. waiting for Doomed or emptied Temporary Monkeys) or additional cards that aren't worth using just for the Monkey steal.
Don't rely on the opponent to leave a space for your side. Shrink does not leave a space, and only cards like Return to Sender, Bed Time, or Expert Negotiator, or Amelia's Grand Disappearance ability, can do that.
When Expert Negotiator is used, the Sun Temple no longer copies the attack power gained from the original sacrifice, instead it gains power equivalent with the amount of monkeys sacrificed on the side of the Expert Negotiator user (bug fix)