I think this is the best Xaku build possible for general use. Range and Power are both at their sweet spot w/out sacrificing Duration or Efficiency.

Swap out Xata's Whisper for something that gives you survivability--like [Harrow]'s Condemn: Grasp does most of the work and doesn't benefit from Whisper.

Arance Energize + Zenurik are the backbone of the build.

The game plan is to get a [Gaze] zone up asap and let Grasp erase enemies up to level cap.

Vast Untime is amazing for sustaining DPS, but don't prioritize it. Condemn, Grasp, [Gaze] to stabilize; Untime to sustain.