As the title says. What is a good spirit?
There is no spirit specifically for martial arts, but there are multiple threads on spirits for fitness, like Sartmulu, a spirit of Mars.
Not exact but close I suppose.
martial arts or fitness requires one to make mundane effort to do activities of those subjects. It’s core is physical training. No spirit will do the workout for you. Human action is required. Entity may stimulate mind with thoughts/images for motivation but it still comes down to your will power to do that action.
Check out Kurtis Joseph. He has a YouTube channel and talks about combining martial arts and magick.
Which part of martial arts? The combative and self-defense skills or the spiritual and mental?
Phaleg, to help you fight in an intelligent and cunning manner, and Hagith to attract either a mentor or an opponent that will help you to improve.