I'd tease a punch from him, probably a straight jab.
Sidestep and suppress the arm, whilst striking into his floating rib, winding him.
As he's stunned, grasp his wrist and apply an elbow dislocation with a forearm smash just above his elbow.
Then, once he's distracted with the pain, pull him off of balance into a knee into the solar plexus.
This would wind him and drive his body upward, increasing the momentum available for an elbow into his cervical or lumber plexus.
The cervical strike would paralyze him from the neck down, probably killing him.
The lumbar strike would paralyze from down the waist down, including his genitals.