Wedding party duel insane NPC damage output

I am trying to beat Olda in a duel at his wedding, but this man hits like a freaking truck, 1 or 2 hits me and the duel is over. Meanwhile I can beat the crap out of him and his bar barely moves. What am I doing wrong?

*update* Beat him. If you're having trouble, don't get stuck in a parry cycle, parry once if you need to and dodge sideways to hopefully get a shot in. Use the pillar in the middle of the arena to keep your distance. Dodge is your friend here; you need your stamina.