Here I will address my side of things, since what people have heard so far was all from rains perspective.

I was on the steam discussion forums and I wanted to commission a mod like this, and Rainmaker offered to do it. We talked on steam and then on discord, I told him what I wanted for the mod and the product I was given satisfied me. We discussed payment after some time. Rainmaker did not have a set commission price (despite typically commission meaning that there is a set price for something to be done, think twitter artists and such) but I sent them $10 anyway. They appreciated it but understandably were disappointed to a small amount, and wanted more. We turned the conversation into an argument, all throughout I was not given a set price, in fact when I offered to pay additionally for the mod they stated "I don't need your scraps".

They later blocked me and claimed I scammed them because I didn't pay them a price I wasn't told. I was also threatened to not post it. I decided that I did want to have the mod anyway, it was partially complete and I had the skills to improve upon it in an amateur way. I was the first to upload the product publicly, and most of the mod is now my own revisions to it, with very little of the code being actually produced by Rainmaker.

TL;DR I commissioned the mod from Rainmaker, gave Rainmaker some money for it even though I wasn't given a set price for it yet, Rainmaker wasn't happy with it and subsequently refused offers from me to pay additionally, and is now saying I scammed them and stole their mod even though I offered to pay more, and wasn't given a commission price.

If you would like evidence, I can provide screenshots of our conversation on Discord, both in an DHT archived form and normally