If you're solo, use ex ball for a solo conversion into SKD. You can use ex if you have an assist too if you want to keep pressure in case they block, and a bigger damage combo if they get hit.
Consider usind jS 236M vanish as opposed to jS 236H. In the case they block, you can use vanish to get plus frames and keep pressure. Less risky than the RPS after ex ball. Beware of f1 anti-airs