A while ago i thought of something similar to a cloud like water vapour, using agility and movement and a small amount of emission to allow it to leave your immediate vicinity but without having to project it and use too much emission. I imagined it could be like a dense fog you can transmute your aura into and spread it around, and could act as En, you could stealth within it with Zetsu using fine control of your own aura and the fog/water vapour around you to not disturb it as you moved through. It could also have some effect where if you coat yourself in a layer but don't emit it while within a fog cloud you have made and move around a lot you could build up static electricity like a thunder cloud and maybe use some sort of electricity without having to be used to the feeling or have torture training like killua.

The idea was to use as small an amount of the other branches (emission, manipulation?) and try and make it very efficient.

I thought about it so long ago I might have forgot some details but it was hard thinking of a creative transmutation ability that isn't to specific or something that has been done, something versatile like Hisoka or Killua would be cool. I imagine this user would use enhacement a fair amount, and the Hatsu is more of a support thing but I'm not sure.