Title says it all. I’m pretty sure that Hellswing the Witch Hunter is the Wraith with a Scar.
- Hellswing’s attire: https://swordscomic.com/comic/CCCXXX/
- Wraith finds his own corpse: https://swordscomic.com/comic/CCCXXXVIII/
The implication, of course, is that the Wholesome Ghosts story arc happens after the Demon King arc, since Hellswing was alive during the Demon King’s takeover.