Build Guide
With the buffs and changes to Sunwuko in Season 12 I've found this build to be incredibly useful and fast for gem levelling and farming Rifts/Bounties.
The basis of the build is pushing for continuous Epiphany via the Obsidian Ring of the Zodiac in Greater Rifts or In-geom when gold farming. When gold farming I drop out the OBR for the Avarice Band with a Gem of the Hoarder and equip In-Geom instead of Rabid Strike, this makes you effectively immortal and gives a massive amount of gold. It's also insanely fast with LTK, Epiphany and the In-geom passive in place.
It can push reasonably high in Greater Rifts for gem farming with the Rabid Strike variant and is insanely quick, you effectively constantly teleport to enemies with Epiphany active, the damage is doubled due to the Rabid Strike effect and your spirit is continually topped up with the Laws of Seph, Desert Shroud, Epiphany and the Reaper's Wrap effect. If spirit is problematic you can switch into Replenishing Light on Blinding flash.
If survival is easy, such as gold/key farming Neph rifts and Bounties then switch out Near Death Experience for Relentless Assault. On the Rift/Bounty Variant with Goldwrap and Avarice Band I use Determination, Relentless Assault, Momentum and Beacon of Ytar.
Note: I'm also having a play about with the Spinning Flame Kick rune on LTK as a variant but I'm not sure if it beats out Sweeping Armada with the clone from Rabid Strike.
I literally have this exact same setup after finding an ancient rabid strike and have to say it works quite well. My LTK rune is on spinning flame kick instead of armada but the firenados and fireball spam is quite luls.