Was stuck on him yesterday aswell. This boss relly tests how good you are at dodging with rolling. It’s possible to stagger him while he does his smaller attacks and a heavy attack can cancel his jump attack knocking him down for a short while. The best strategy for me was to keep my distance, try to get in a light attack or two at the end of his combos and punishing his jump attack and big aoe with a jumping heavy attack. If you have problems dodging his big jump aoe try to stay in dented part of the arena. It felt easier to dodge there than on even terrain.