So I was kind of hoping this design would be used for the SAT, since false or at least sliding walls are a pretty large part of traditionalist japanese culture.
The basic design of the operator would be a defender, who has the ability to set up 1, or maybe 2, single wall panels, roughly the size of a small wall reinforcement, that can be interacted with. When interacted with, the defenders can open the wall, and their character will walk through the opening, and then close the wall behind them.
For balancing:
The placement of the walls will require a very large amount of time, possibly 5-10 seconds, to cut through the wall with, say an electronic saw, or something similar, and then hinge the wall back on to form a door.
Interacting with the door will require the defender to face the door, so they don't accidentally open it while reloading,and won't be an action that can be cancelled.
As a tradeoff for the walls being, effectively postern gates for the defenders, they will only be able to be applied to non reinforced walls, meaning they can both be shot through and even destroyed by the attackers.
As a result of this, meaning that the defenders will most likely not set these walls up in immediate proximity to the objective, the defender equipped with these wall hinges will need to be a 1 armour, 3 speed operator, or possibly a 2-2 with enough pushing, in order to actually get to their setup location.
Attackers will be unable to distinguish the difference between the false walls and the real ones, from the opposite side to which the false wall was deployed.
On the side that it was deployed, there will be a small insignia (possibly the operator's insignia) indicating that the wall is fake, and this will be visible to both attackers and defenders. It will have a slight glow to it from the defender's HUD, and will be scannable by drones to ping the location of the false wall for attackers too, which, once scanned, will also add the glow to the attacker's HUD.
For clarification, the glow will be on the insignia.
The Operator
Due to the nature of the operator, a primary with a suppressor, similar to echo, is most likely the best option for fitting in with the theme.
A shotgun to swap out on either the secondary slot or primary slot, also with a suppressor, will allow the operator to perform a roaming function.
They should be equipped with barbed wire and impact grenades.
Synergy and Why Should I Care?
Well, with the introduction of Jackal, the attackers have a much easier time of pinning down roamers. Not only would this be a small, but needed, imo, nerf to his roamer-hunting potential, it would allow for much more intricate team play, especially with Caveira, on flanking manoeuvres.
Especially on maps such as Yacht or even Oregon, where the attackers have a fairly small advantage from the get go, and an obnoxiously large one once the roamers have been eliminated, this would require the attackers to drone properly, to use jackal as a sweeper, to make sure the defenders don't have any nasty traps set up.
Picture the scene, you're in Oregon basement push, your team has full control of lobby and meeting. The hatch in lobby is open and the team is pinned on the bottom floor. You're aware of a caveira sat above lobby, but have someone watching her. Then, moments later, your two guys covering meeting are dead, and one of them is being interrogated, because there was a false wall leading into catwalk and she flanked them.
It's just an idea, but I think it has potential. Let me know what you think.
Edit: The operator should be called Phantom, Ghost, or Shade, or something similar. Something to fit the theme with walking through walls.