Kwami swap with Papillon!Adrien (Greyling) and Chat!Hawkmoth (Tuxedo Cat).
By some misfortune of the universe, Gabe ends up with the Cat Noir miraculous in the first place and Ladybug, dispensed as the yin to his yang, is tasked with getting it back. Naturally, he wants her miraculous too and wreaks havoc all across paris to lure her out. He is ruthless with cataclysm. Ladybug has to grow up a lot quicker to handle a guy with the power of destruction trying to kill her, so Mari ends up being a lot more serious but very in control of her double life.
Master Fu recognizes that she’s in over her head when one day Tuxedo Cat comes out to raise hell and Adrien, a civilian currently sneaking out to go to school, has to step in and help. Fu sees his potential and gives Nooroo to him. Gabe being Tux is like “Shit I put my son in danger” and puts Adrien on basically full throttle house arrest. No matter! The butterfly brooch holder is a distance fighter anyhow.
Greyling is born. Kid, you are not subtle with your names. Anyway, the akumas now sort of work in reverse: whenever Tux attacks, Greyling asks civilians for their help sending him back to lick his wounds/better yet, get his miraculous.
And the important stuff: the love square. Ladybug, though grateful for the thought, is not a fan of Adrien risking his life to help her that first time, but after that doesn’t have much contact with him. Marinette and Adrien don’t interact much either to begin with. Adrien still obviously loves Ladybug (so selfless, brave, and kind). The mutually reciprocated ship is Greydybug: Ladybug slowly begins to fall in love with whoever keeps sending help to her when Tux attacks though she knows very little about him. Unfortunately, in this au, a reveal is a death sentence, frustrating any attempts at them actually getting together.
Adrien has a lot less of a facade in this au since his dad is even more distant. He sometimes acts out in non-malicious ways to try to get attention and ends up anonymously forging a camaraderie with Mari. Since he’s more in tune with his emotions, Greyling sometimes accidentally ends up possessing his heroes in his desperate desire to help ladybug (which we see about to happen here). He’s good at it but is constantly horrified when his transformation drops and he realizes who he is again.
Anyway I fully support Papillon!Adrien and yall should too.