Given what I've read off the thread, I'd say he'd succeed after blasting through every PC and every force my character would manipulate between him and her. She could teleport away all the time until he started getting a magician to follow her magic or scry her location. She could walk into the realms of the Gods for some peace and quiet, but he'd be right behind. She could go to the inhabited moons and he'd still come. Every step of the way she'll try to convince him not to. She'd get creative and he'd just... keep on coming. She'd make deals with fell Gods and manipulate the stuff of the world unconciously, while he still came for her. She'd create spells for hiding the soul and worse, but that asshole would just persist and make deals with demons/gods.
When everything has failed she'll finally try to murder his shit from afar, to be sure it'll happen, enchanted arrows covered in magic poison from a range he couldn't possibly see, but he does. Or he gets hit, but it doesn't wound him as it would wound a dragon. The hell? She'd fly above him, but he'd get artefacts granting him flight as well. She'd breathe underwater and he'd follow.
She'd fight him every step of the way. She has fought dragons, shadows, bandits, medusae, mages, soldiers, undead and worse. She has talked with many important figures and caught the attention of several godlike beings. She'd fight him and she wouldn't be able to win.
All she can do is stave off the inevitable, while the world burns around her.