Oh, if it's okay, I think I'm gonna resubmit this:
Ability: Telepathy
New effect: "The Pokémon sets Wonder Room when it enters battle."
Wonder Room is an existing move that swaps every Pokémon's Defense with its Special Defense for five turns.
Competitive reasoning: Wonder Room is a truly fascinating move, but the fact that it takes a turn to set it often undermines it, since its power level is so much subtler and harder to abuse than something like Trick Room. Being able to set it on entry turns this around, letting you use the Pokémon as a pivot to prepare the rest of your team for dealing with any sweeper that targets your weaker defenses or any wall that shrugs off moves from your stronger offenses.
Note that using Wonder Room while Wonder Room is already active turns it off, so unlike, say, Drought or a Surge user, this allows you to change it both ways - switching in a Telepathy user is less "setup" and more "toggle." A Pokémon with Telepathy that's capable of pivoting often can ensure that Wonder Room is always giving your team the upper hand.
Flavor reasoning: Telepathy is already a defensively oriented Ability that's largely associated with Psychic-types and Pokémon with a strange connection to the dimensions, so it makes sense that they could twist them this way.
Notable buffs: There are three Pokémon that jump out as having the potential to take advantage of this in wildly different ways, all of which are in Galar!
Noivern is the fastest Pokémon with Telepathy that's currently available
Tapu Koko isn't in Galar yet, but Telepathy is also unreleased even then, and it also generally runs a pivoting move in U-turn and plays a role of offensive support for most teams. Noivern is on the frail side, but its ability to set Wonder Room and then switch out before taking a hit opens up new opportunities for the rest of its teammates to take advantage of whatever Pokémon the opponent sends in.
Beheeyem's niche is the opposite of Noivern: rather than being the fastest possible Wonder Room pivot, it manages to be the slowest thanks to its access to Teleport. It might take some stat buffs from the next stage to get it there, but I think Beheeyem could become an excellent defensive pivot that's able to switch in and take a hit.
Despite being mostly an offensive Pokémon, Gardevoir actually has above average special bulk and could realistically play the role of a special wall. It also has useful support moves like Will-o-Wisp, Trick, Healing Wish and even the excellent Wish + Teleport combination. Unfortunately, it's held back by its abysmal physical defense - but with Wonder Room allowing it to swap its defenses every time it switches in, careful play can enable it to wall opponents on both sides of the spectrum (and especially take advantage of Will-o-Wisp, which is strongly biased towards physical walling) so long as it switches in at the right times, while its base 125 Special Attack and access to Fairy STAB should allow it to keep up offensive pressure while it does.
+
+
(
)
