The easiest way to do this is to control Muzet and link with Ludger as your AI. Muzet's "Support Wrap" ability is easy to activate simply by front stepping or back stepping while guarding. Ludger's ability "Mirror" will simply copy whatever your controlled character's ability is.
You can literally grind this one out in a matter of minutes doing this, since you can use the ability as fast as you are able to back/front step. Although you have to use it a total of 450 times for the trophy, it's still very simple and one of the easier "ability" based trophies.
This video showcases both the "Mirror" and "Support Wrap" abilities at work.