It could be a rival who is a mercenary swordsman. He could be like looking for me for somethng. (not to kill remember just a rival) He could be looking for me because he is looking for an artifact I have stolen from one of his bosses... (mercenaries have more than one boss you know) It would be cool if you get to fight him 4 times and everytime you fight him/ meet him it's a sidequest. 3 times you fight him as me alone and once in a party that must have me in it.

1. alone
2. alone
3. party
4. alone

And could you put this song as the battle song everytime you fight him??
"Makavelli bomb first" by tupac. Actually just the beat of it. That's if you can take out the lyrics.