The Malevolent Witch by M.R.Gross
The day the earth lost power more than half the world's population was wiped out. That fateful day was also the day that magic returned and with it every fantastical creature and race. Khayin, a man with a mysterious past, a bounty hunter, moved from one small village to the next while passing through long abandoned cities. He tried to live as simply as he could, until one day an unexpected bounty landed in his lap, a witch, that even in this fantasy world come true, was only thought of as myth.