[Boreal's Contempt] focused [Guandao Prime].

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Press F for old Berserker mod.
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[Guandao Prime] is slash focused weapon.
You can replace [Primed Fury] to [Quickening] or [Gladiator Vice].
You can replace [Sacrificial Steel] to [Gladiator Might] combined with [Gladiator Vice] for 240%CC in 12x if you want to and only requires 3 formas for this build.
If you feel like the attack speed from Gladiator Vice isn't enough there's Arcane Strike.
Weeping wound for the extra stat chance to proc stats.

IF you're casual-ing through content, you can:
1. Replace faction mod to [Carnis Mandible] to increase the chance for slash to procs even more than impact.
2. Replace faction mod to riven. (+CC +CD +aspd) or (+CD +range +aspd).
3. Replace faction mod to Gladiator Might or Organ Shatter.

For the riven mod it's best if you get MINUS impact/dmg to infested/cc in slide atk

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Q: Why [Primed Reach]?
A: More range means you can hit bunch of enemies at once hence increasing the combo faster and lethality.

Q: Why faction mod?
A: The damage is multiplicative instead of additive.

Q:Why [Twirling Spire]?
A: It's just preference. I prefer 360 degrees spinning move than mobility in attacking. Feel free to use other stance no one's stopping you. And also [Bleeding Willow] has pretty similar attack patterns with [Shimmering Blight] that posses the same polarity with [Twirling Spire] so you can change it anytime if you don't like it.

This is the build if you're using Arcane Strike or attack speed frames such as [Wisp] and [Volt].