I'm sorry to ask, but what was his original purpose

I'm not sure if I actually gave it before or how detailed my description was (if there was at some point).
I have so many stories that I scrapped that my characters actually have really fleshed out personalities, but I keep forgetting that I am the only one who actually knows about them. Most of my characters must seem like they simply exist, without real personalities or purpose?

But this wasn't your question, was it?
I'm not sure how "different" the purpose actually is, depending on the point of view.
Originally he was forced by his parents to join the military. But he couldn't take it for long, mainly because someone picked on him and he couldn't take the tone. That's why he tried to flee twice, allowing the army to shoot him for desrtion. During the hunt for him, a bullet hit his ring, causing it to deflate. Upon finding him, Flint offered a deal: He could leave the military if he started to ask people to inflate the ring with farts. What I was always unsure about was whether the complete deflation will be lethal to him or not. But in both cases he wasn't allowed to fix it, someone of the army always watching after him to check this.
In short: He was forced to get his ring inflated with farts and didn't like it. His personality used to be very calm and shy.

This version is very cheerful and playful.
Getting his ring inflated is actually something he enjoys, which is why he installed the funnel.
He learned that quite some people would actually pay him to do it and so he started to offer it. He also lets people mess with his ring in other ways, often leading to some damage. Unlike his past form, he is allowed to fix it though and won't be in danger if it actually deflates. And there is no force behind it at all

So it really depends on your view if you call it a different purpose. Both forms get their rings inflated with farts but the motivation and circumstances are completely different for both.

I'm sorry for the long answer XD

All good! Thats accully very nice to see know his story now and the changes. I'm not such a fan of bondage, but i really like "willing bondage" , like getting farted on without willing to get farted on, but liking it anyways.