Before the fight use the R2 of the Havel's Greatshield to give you the buff that gives you hyper armor and deflection for 40 seconds. Then unequip Havel's Greatshield and buff the War Pick with CMW. This is to give you extremely high counter damage on the R2's. Not only will you generally win trades, but the deflection of the Havel's Greatshield buff is useful as well since if you ever trade with an opponent you'll almost always either get a Leo counter (approx 68% increase in total phys damage) or an instability/stagger hit (40% increase in total phys damage). Combining that with the AR boost of a Dragon Roar will give this build an extremely high damage output. You can also unequip the Gargoyle Tail Axe if you want to use the Greatsword instead of the War Pick.