A very good way to get an S busting level is to use Advances. It seems necessary for some Bosses such as Bass. Some good ones are: Life Srd 3 (line up Elec, Heat, and aqua Blades. Buy them or get them from Green Mystery Data in WWW area 1); Arrows (Double, Triple, and Quad Needle); and Ultra bomb (Lil, Cros, and Big Bombs).