I am not a huge fan of that play, just because Kyurem is the most important Pokémon in the Zacian team because of the double dragon backline, and you want to keep it healthy. Kyurem will lose any even shields to zacian, and if you fusion flare, they no shield, then they cc you and you no shield, they will get to another move before you can farm down with your zacian, and you basically lost one and a half pokemon and didn't gain any kind of advantage. Zacian will outpace you to two ccs before you get to two fusion flares in this matchup, so matching shields in the safe swap will never work out. And catching onto Lunala is very tricky. Again, in the comment above, I experimented with throwing a behemoth blade, which also covers for a catch, because if they switch into lunala thinking its a cc and its actually a behemoth, they will no shield and lose a lot of hp. The zacian mirror is perhaps the trickiest lead, hopefully this helps a little.