Pyracantha like I’m sure youve seen, make excellent bonsai. But I’m not sure what your showing in the pic? Is this pic half way up the tree? Do you have any pics of the base? If you don’t, take a few and post em up! If collected properly, a healthy pyracantha will back bud from old wood and should give you lots of branch options. The drawing is rough but I applaud you for making an attempt. KEEP SKETCHING your ideas. Always a good idea IMO.