If you've ever searched for builds around this sword you might have stumbled upon this guide, that one or others. Since it was implemented back in Prophecy I've been using it. I love the real uniqueness of this thing so each subsequent league I tried to make it work differently, be it as statstick or main damage source. So far 8 builds have proven themselves to be quite useable for clearing maps. I don't know if they're shaper viable because I'm a casual, but some did Atziri/Council.
Stuff about the sword
General Mechanics Refresher: The minion itself takes the stats of the weapon to scale itself which means putting Quality on it increases it's effectiveness. It's also almost immune to any kind of damage and won't die to stray damage like a normal Animated Weapon would. It's immortal and it's unlikely you'll even see the HP bar of the thing drop.
Any Support Gem socketed into the sword will support the Manifest Dancing Dervish Skill similarly to The Whispering Ice meaning the sockets don't have to be linked to one another. The skill used by TDD is a monster Cyclone Attack. Contrary to player Cyclone it can be supported by Multistrike or Ruthless, else normal Melee Support Gems or Minion Gems do the job. If you put an active skill in there, it will be unusable once the Sword is active. The Gems still get XP though.
How to better get sword?
In 3.2 the Big Brother of TDD was implemented, "The Dancing Duo". This summons two whole sword minions in contrary to one which means 100% more damage, 100% more rampage stacks on unique boss hit, more map clear coverage and 100% more fun.
To get it you have to fullfill the "Dance of Steel" Prophecy which requires you to kill the Boss, The Steel Soul in the Tier 13 Arsenal Map while either wearing TDD or just having it in your inventory. The only modifiication will be the addition of the mod "Manifest Dancing Dervish also manifests a copy of Dancing Dervish". The sockets, Attack Speed aswell as the Physical Damage modifier won't be changed so having a high rolled base is recommended. The sword will then require a level of 65 which is only 7 more than the base version of the sword but this is by no means anything fun breaking.
The in-game currency is available at the professional online gaming house. The interested gamers can poe currency purchase from those professional online gaming houses in the most affordable cost.