I will do the counter to the play that came before me. You can see the position I leave him in. I will break the arm and throw him to the ground quickly.
Having attempted to apply a ligadura mezana, the 1st scholar has over extended their elbow, losing conrol of their timing and momentum at the point of their greatest structural weakness. As the Counter Master, you exploit that weakness by countering with a ligadura sottano (lower bind).
Lock your elbow close to your body, and turn your left hip forward, reaching across with your left hand, bracing your right. This will break the scholars momentum, put you into a solid balanced stance, and allow you to go on the offensive. Timing is critical. This needs to happen at the very moment depicted by the 1st scholar.
Step forward so that your right hip pushes underneath their left. You have now stolen their centre. As you do this, turn your right hip forward. This will twist your opponent clockwise pushing their left hand into the small of their back and leaving you both facing the same direction. To complete the ligudura sottano, keep your back straight, your elbows in, and push down on the back of the shoulder. Depending on exactly how you hold yourself here and adjust your leverage, you can tear all the ligaments off the front of the shoulder socket.
You can step forward and kneel on your right knee, driving their head forward and into the ground. Alternatively, you can make a volta stabile and kneel on your right knee, which will spin them in a circle. Either works equally well. It really more depends on where your momentum is going in the moment, and where you want to put them.
Since you are holding a dagger, before pushing down, place the dagger tip at the base of your opponents skull. As you drop your weight tightening the bind, it will simultaneously push the dagger through the neck.