I think you have an interesting concept of an evil girl doing evil shit, but you got a lot of work to do before that concept reaches its potential. I do recognize the effort that was put in and that's something to be applauded, but I'm not going to say it's great when it's not. Pain girl and her Demon are fine enough personality wise but Tihi falls flat in that regard, in fact most of the cartoon fails to get a reaction from me and falls flat in It's humor and even action. The jokes don't land (except the skeleton, I liked that), the action doesn't feel engaging, punchy, or fun to watch despite the effort with making it gory, and the characters aren't fun enough to keep my interest. Tihi especially feels too generic in the way she acts and responds to the world, maybe change how she and the world reacts to Pain girls violence cause evil girl doing evil things doesn't mean much if nobody has any fun reactions to the violence besides joining the fray.
I hope to see you improve in the future but please take notes and be willing to change what doesn't work.