What to do with soak?

I have Flight, Smiter, Ignightmare, Cygness, Neon and Scythe. Flight already has photosynthesis, should I put soak on Cygness or save it or make another flight and soak on him?

Soak will be useful for other monsters such as Hippogon, Vertedeath, Felicity, etc.
Do you feel that you will be using Soak a lot with Cygness? If yes, then, it's worth putting the skill on it. Pewgway is also another choice as it usually serves as a tank and will definitely utilize Soak very efficiently.
However, if you don't feel that you really need this skill for now, just save it.

Well honestly soak is useful in farming or to pass some hard maps but in ladder and pvp it's kinda futile since you can't trigger soak in ladder and in pvp now it's really easy for yiu to get a 1 hit ko