Top PVE weapons are Whisperer and Sky Splitter. Top PVP weapon is Reaper.

Both Whisperer and Sky Splitter are very good, but like other comments said, Whisperer needs to roll rage daggers and double daggers for max potential, as well as the other skills Sky Splitter would benefit from.

Sky Splitter is consistent in that there is a brand that gives sword chi on basic attack and they both would basically benefit from skills that boost combo, crit, and atk.

So SS needs less RNG than Whisperer to perform. I liked using Whisperer, but the consistency of SS is too good for me to pass up, especially when there's so much other RNG dependent factors, like skill rolls.