an undertale-styled battle in gamemaker studio

A little project which is basically an Undertale fangame but combined with other characters! I know a bit of code, but it is still not enough for me to code something reasonable. Basically, I need an RPG battle styled like an Undertale one with two different outcomes (also like in Undertale: you can either kill or spare a boss). It should have a game icon, then jump right into the battle, perform a battle and then just end. We have sprites, music and almost completed plot: all we need is a decent coder who can nicely cooperate with me and the crew :) I'm very open to suggestions and even more open to people who will be interested in the project on a personal level. Seeing how well the fanbase liked the teaser, I assume there is a bright future for this project! (Since it's a fangame based on other peoples work, the game itself will be free but there are people willing to help us with donos. For this battle I'm willing to pay with my own money. Also, i would have to ask to not spread the spites and music since it's an original work of our artists.)