I will have a fight with a chair that is type undertale Xd

I have an idea, I'll make a fan game where all the characters have 3 phases when fighting (something like in undertale last breath but instead of sans I do it with other characters). I will be uploading the things that I will do in the game.

Does anyone know of sudden changes ?, Well I did a fight against sans of that au, it is not better than FDY but it is something. link: https://scratch.mit.edu/projects/437697592/