Xaku is mechanically my favorite frame, so I'm determined to find a solid build. So far this is Arbitration ready -- Needs ESO and Steel Path testing, will update progress.

Update 1: Swapped armor for health, added some regen Arcanes - updated build guide with descriptions of usage.

UPDATE 2:

• ESO is so far so good, so is the higher tier pushing and defense/Lich and Sister farming.

• Updated the range, reduced strength
  A lot of the offense of this build's strength comes from the level modifier for the Grasped weapons (weapons increase damage based on the level of the enemy pulled) and the void buff,
  therefore,

• Added more duration/reduced efficiency a touch (with a solid Dethcube Energy Buddy and Zenurik, this isn't that hard; Madurai if you want raw damage on your weapons.)

• Added more range (Range increases the amount of guns pulled, how far they are pulled from, and their pew pew distance).

THE MOST IMPORTANT EFFICIENCY TIP IS TO ALWAYS CAST VAST UNTIME FIRST SO THAT THE COOLDOWNS FOR THE OTHER SKILLS ARE PAUSED

Vast Untime is what this build is centered around -- Remember, you have a 75% hit reduction; which includes hit scan, so KEEP MOVING

Cast Vast Untime, Grab as many weapons as possible with Grasp of [Lohk], (casting Grasp of [Lohk] until it won't cast anymore is a good indicator that you have full weaponry, that or the buff meter at the top: you should have 12 16 guns with this range at max rank)

Then top it off with your Xata's Whisper - This will last a minute and does not need to be rebuffed very often unless you let Untime go too long -- However it can be rebuffed at any time.

The point of the build is to maintain your turrets as a defense platform and be a continuous powerhouse in a permanent Untime state.

If you get into trouble, the range and power of Gaze will hold down a big enemy, or tear their resistance -- Remember, [Gaze] can drop their damage reduction by 100%, this is an important utility for tougher fights.