Clarification with "The Barber"

[Astig-1979]

Instead of dealing direct damage, your Spirit Barrage now accumulates on the target. When you stop casting, it explodes dealing [400% - 500%] of the accumulated damage to all enemies within 15 yards. (Witch Doctor Only)

All the while, I just took this item for granted and just kept attacking with Spirit Barrage and wait for them to die…

So today as I was doing a GR130 with a freshly built WD. Against the RG (Perendi?), I kept casting and casting… RG’s health barely went down… So I decided to look for any Pylon, stopped casting, moved away then boom RG dead!

I tried again on another RG the same method, but no go. Seems like I am missing a step or something.

I watched Wodijo’s GR150 HC video and he did the same thing: RG ~80% HP then dead!

How do you trigger the “stop casting” part consistently for the massive damage?
Last time I played Mundunugu was so long ago, I forgot the details.

PS: I dont have COE equipped, so it is not about “timed during Cold cycle”.

According to an old thread:

@Kindran-11838

FAQ:

• Should you continuously cast Phantasm or let it accumulate?
  Answer: As long as the mob doesn’t walk out of Phantasm range while it accumulates it literally doesn’t matter. If the mob is going to move from Phantasm range go ahead and forcibly explode the Phantasm by casting a 4th+ at the new location
• Why did the guardian instantly die from x%?
  Answer: You accumulated enough damage to kill it.
• Why does the boss get hurt when I channel Spirit Barrage, but not when I let it sit?
  Answer: You forcibly explode the Phantasm when you cast a 4th+ Phantasm. The boss will take damage when the Phantasm explodes early or at the 10 second mark. Both will deal the same damage over time.

Hmmm… Maybe I accumulated enough “potential damage” and it killed the RG instantly then…

So I should just keep attacking…???

[Kirottu-2131]

General Spirit Barrage cycle with The Barber is following:

1. Cast 3 Phantasms without channeling SB.
2. Start channeling SB to build up “charge”.
3. Quickly recast the 3 Phantasms to detonate the built up charge.
4. Repeat.

It’s a mechanic that takes a bit getting used to but once you get the basics, it’ll feel more fluent.