Herald of purity + Minion Instability?

Answered my own question.
The dagger "No elemental Damage" cause the Purifying Flame's "50% physical to Fire" conversion to be unusable. So its a 50% reduction damage.

No problem, we still have Etheral Knives and/or Blade fall as physical spell without conversions.

So which one is better?
Blade fall for the range and higher potential damage?
Rtheral knives for the faster cast speed and constant damage?

Update from last time, so here's what I found out.
Blade fall is better since you have a bigger range and better hits. I've seen etheral blade miss a few times for no apparent reason so I'm assuming its from accuracy or cone is shorter then the visual. Regardless Blade fall is the better option.

One of the fun thing I found out is how Herald of purity triggers. It triggers on kill most of the time, but won't trigger but itself (Obviously)
BUT, the Siegebreaker (Caustic ground) effect, is not considered to be from the Herald of purity, meaning if a monster dies in the caustic ground, it will spawn a Sentinel!

What's more, its can be done from ANY caustic ground effect, again meaning you can use skeleton's caustic ground effect to trigger Herald of Purity.

The only issue I have is the tankiness of the minion is too high, but Maligaro's lens + Nercomancer Aegis fixes the problem until I can get Fortress Covenant (2 EX wtf?!) for the sweet "Notable Passive Skills in Radius are Transformed to
instead grant: Minions take 20% increased Damage"

So far its working GREAT! I've switched to Skeleton and Bladefall while mapping so Skeleton Life and Bladefall dps is very low, but I already see a big improvement.

Lets see how far we can go!