There are various solutions. One: Build you endurance until it basically does no damage, then hope to land your hits. Two: Build you favor with Ragus, Vint, or the goddess of war (Don't remember her name atm) to gain the titles from them. After that, train your stats to be strong enough to beat it.
three: Wait until you have many more titles. I know this sounds like the last one, but you can also gain titles through leveling specific stats past a certain point.
The first time i beat it, I had just focused on training endurance and then beat it. The first hit may cause a lot of damage, but every hit after that should be fine.
Now that I have many more titles, it is a rather easy fight to beat since my stats raise by quite the amount quite quickly.