freeze with vordt, get to heavy morning star, use fire paper before the last bleed hit(or after, whichever you prefer, but in that case you might as well use a fire ceastus)then go back to vordt, repeat.
I upgraded this yesterday and tried it out on my Str build. The stopping power on it is tremendous. You can R1 stunlock the red-eye Lothric Knight at the beginning of Lothric Castle and take 0 damage (4 hit kill). For the Cathedral Knights with shields in the Walled Garden, two R1's to their block sends them into instability frames for an easy reposte. The Frost damage is just gravy. Also the WA Perseverance helps some on bosses to take less damage and get more than 1 swing in. My only dislike is the graphical frost effect on the weapon as it is distracting and takes away from the look of your armor. I find myself switching to my Light Crossbow as I'm running around the Firelink Shrine just to get a break from the blur. But other than that, this is a great weapon that you can be using right after killing the Tree boss.