Really cool stuff. Defending the standing guard pass. feet to butt is the basic principle for closed guard pressure. On their second step of their standing guard pass, pull them down.
Or, after their first step, put all your weight through their opposite hip to prevent the second step.
You can cup their elbow which will be posting on you, and sweep them by attempting you shift your hips 90 degrees, and swinging the far leg out, as in a pendulum sweep, you can sweep over to mount