Are you in Mox or Friendly Fire? This should be emphasized: 16m Kephess should *not* be nerfed. It may very well be the most difficult encounter yet, but, at least for my guild, we're still excited and progressing in the fight. If in 3 weeks, it's still alive, go ahead and nerf it.
ehm... why would you assume ff and mox want kephess nerfed ?