252/88 Ferrothorn takes 96.87% damage minimum from CB Freeze Shock.
Of course if it has Protect and your opponent predicts FS it can switch in on the charge turn and Protect the next.
If Kyurem-B has already charged though nothing other than Cloyster and Heatran switches in safely, and even those won't like the 30% paralysis chance.
Most player won't expect Freeze Shock so it's unlikely that they send something faster on the charge turn (such as Palkia or Grachomp). Arceus-Steel is still a problem though.
Pairing Kyurem-B with Magnezone is a must in my opinion, since it gets rid of the annoying steel-types that do wall it. Those being Arceus-Steel (without Earthquake/Earth Power) and physically defensive Forretress.
Specially defensive Forretress has a chance to be 2HKO'd by CB Outrage after SR and has a high chance to be 2HKO'd by CB Fusion Bolt even without hazards.
Standard specs/scarf Magnezone is 2HKO'd by CB Outrage all the the time and scarf Flash Cannon has a chance not to OHKO Kyurem-B after it has taken SR damage (who uses ScarfZone in ubers anyways).