Side view battlers

How can I hide battlers in sideview using a script? I can't use yanfly action sequences because I need to setup when and if they will return visible

you need to give a better description of what you want to do and how to use it.
There are several ways that might fit your question, but each of them has different advantages and disadvantages.
It wouldn't help you to get an answer that clashes with other things you want.

I want to make a skill with a common event and during all the common event the side battlers should be Invisible, after the common event they will reappear

try something else:
have the first command on the common event be a show picture that places a picture of the battleback on the screen, hiding the battlers behind it.

if that doesn't work, yanfly's action sequences would be the best solution, just have them call the common event when you want it executed.

Something like that: