I am the counter to the first remedy master of dagger. He badly played the remedy so I was able to take his left hand. And from this grip, I can put the dagger in his back.
You are attacking your opponent with a fendente strike and they have defended themselves as the first master of dagger. They have hooked their left wrist under your dagger and then rolled their hand over to catch your wrist. Although they have successfully defended against your initial strike you can still maintain the initiative.
Before they can respond with a suitable play, reach forward with your left hand and grab the point of your dagger. Pull it down against your right forearm, pinning your opponents left wrist between your dagger blade and your arm.
As you do so, turn to the inside and roll your elbows back to your hips with your hands pointing down and forward. It feels like a cutting motion. This will cause your opponent to pivot around as shown. Slide your left hand off your dagger blade to grab your opponents left hand. This will hold them in place long enough to use your, now free, right hand to deliver a second strike. Aim for either the kidneys, the back of the neck, or the armpit.