Hard to say who might win but if the author intends to make this go down to the wire (where the final battle decides which side wins) then there is a high probability Jack will win this fight.
Based on the previous 3 matches then this next chapter will likely be the last, so we will see.
With the way they made heracles' character, bet once he has made jack to repent his sins, he will just be like aight im good call it a draw. Coz no way is jack winning and no way is heracles losing.
This fight can go however they want, and while it's easy to imagine Herc winning in a satisfying manner, I can think of a very real way that Jack can win.
If Herc crushes Jack's hands, thereby destroying the gloves and killing his Volund, he would be killing an innocent, inadvertantly having crushed the life of a young girl unwillingly made to help a madman she hated due to overwhelming fear. Given how Herc is portrayed here, that might suffice as a sufficiently damaging mental attack.
It has a basic B Plot with the Valkyries and their motivations in why they join Humanity's side, but otherwise it us lvl basically an excuse for the long battles.
I'm surprised the Jack vs Hercules battle is dragging this long (this chapter feels like filler....) since the previous battles were an average of 7 chapters long. Hopefully the wait for the next chapter will be worth it, but I feel right now that it should have just been a super long finishing chapter like the previous fight.