And so the old man does a forward flip with a ~170 pound tiefling on his back.
...
Well there's a mental image.
His attack succeeds, but now he's an old man ninja lying on top of a incredibly fit half-devil ninja in the prime of his youth. One who has a... significant level of experience in horizontal acrobatics, I might add. The elbow does little to prevent Kal from attempting to grapevine his legs around the old man's, then hurl him off and sit on him in a rather standard mount position, where he can grab the old man's arms and twist them behind his back, locking them in place with his full weight.
"You know, I tend to find myself in this situation more than you might think."