The Dragon doesn't seem to fly very high when it attacks, so perhaps Susanoo can keep jumping until it reaches it.
Susanoo can also just
fire its firearms all the time and let the telekally attack do the rest. Each successful attack counts as several and also creates shock waves that hit the target itself and the surrounding area as well.
If all the purple "lasers" turn around (seriously, Susanoo can fire his weapons forward and the lasers do a 180 degree turn to hit whoever is behind him)