This is a very interesting fight, let's dive into it.
Starting with AP, KoF is a very outdated verse here on the wiki (working on it is in my schedule, but very far in time) and the calc used is both on an external forum (therefore not accepted) and the suggested results range between not even low 7-B (500 kilotons) and well into it (5 megatons), and I don't know what a mid-end could be. Terry can both be in great advantage and disadvantage, but never in one-shot range, I think. (Jon is 1.67 megatons).
Anyway, ignoring it for a second, Terry is surely more skilled in martial arts due to having an extensive training in various styles, but Jon should be able to keep up with his own skill, without though matching him.
In terms of experience they are somewhat similar in sheer numbers, but Terry is used to fight martial artists, while Jon ha experience with monsters, most of which rely on unconventional fighting styles and weird powers, so Terry may have an edge even here.
Jon is a more deadly fighter though, he doesn't have problems in killing his victims, claws and fangs are also dangerous tools, when Terry doesn't wear any armor and relies on his fists and kicks. Nunchaku are also a handy weapon.
Jon is also better in terms of mobility, because he possesses better acrobatics out of sheer physiology and showings (I will definitely improve the description, sooner or later)
In ranged fighting Terry has the edge in normal projectiles, given that he can use them as much as he wants, while Jon's only projectile is the very strong burning Dragon Cannon, but he can't pull it off at any time. Terry's projectiles mostly travel on the ground in a straight line, and options such as acrobatics and beast cannon should help avoid them and close the gap.
But what I think definitely turns the ties is Jon's speed amp, very useful in a setting where speed is equalized, and his aura would definitely have a devastating effect on Terry. We don't know the range nor the time it employs to have effect, but it is stated to be something that you necessarily need to resist in order to hunt the Darkstalkers, as such it should have rather quick consequences.
Finally, Jon has an astronomical advantage in lifting strength, better stamina and I'd dare say even better senses.
I vote Jon due to his aura, deadly weaponry, higher LS, better acrobatics and speed amp, on top of all the small other things, which I think would let him triumph over martial skill, better projectiles and possible higher AP.
