Stick and move- go in for a hit and move back. Avoid the shoulder blocks. Don't bother going in close for combos, he'll just beat you more. He's open for shots more when he makes his taunting gesture.
At about the halfway point of his health he starts with the hammer attack. keep your distance and use projectile attacks. he'll spin around and use an attack with the hammer that covers the entire arena at ne point- use two long jumps and a double jump to avoid this. Eventually he will go down for good.