Hello! Thanks for the feedback!
We've noted down these bugs and are currently working on fixes for the combat. Currently balancing is not done yet, some characters are super strong and some are lackluster or straight up weak. A 2x speed is something we do have planned but since the game is full of bugs and is still in early development, it would probably not be worked on anytime soon. If you have any suggestions regarding the rotation battle, please do share! I'm always looking forward to improve it.
It would also be great if you joined the discord as thats the fastest place for me to track and respond to bugs and announce new updates. Also, the japanese font will be updated soon. Once again, thank you for your feedback!