I could help you out, though i am not a professional i have earned quite some experience with RGSS over the past years. though i cannot tell you until you dont show me what you have so far.
i dont have enough time to build a complicated battle system from scratch.

you might send me the a detailed description of what you need and what you have so far, you can send me the code also if you dont mind, though i can only tell you whether i am going to help you or not after i got the information since i am busy working on several own projects right now.

if you would like to have a look at previous works of me so far you can send me a PM also and i might show you some systems i made in the past.