My Quest To 2HKO Skelegons!

I've always been fascinated with the idea of finally being able to 2HKO Skelegons. Currently I can 2HKO them with Ciders(20 ATT pot) but not 100%... more like 40-60% of the time.

Equips:

54 ATT Shinobi Bracer.
30 ATT Balanced Fury.
15 ATT Stormcaster Gloves.
11 ATT Naricain Pendant.
5 ATT, 1 slot Pink Adventurer Cape.
2 ATT Facestompers.
20 LUK Sauna Robe.
15 LUK Zakum Helmet.
10 LUK Rose Earrings.

Clean Range: 2222 - 4045.
Range with MW 20: 2424 - 4418.

Questions:

• What's the range needed to 100% 2HKO Skelegons? This is maybe a hard question to answer.
  
• What should I upgrade?
  

The problem is that Night Lords have about 19% total skill mastery, while other classes have 54% total skill mastery, or 72% skill mastery (DkK's) which results in much more stable damage, so you can't really say that it's possible to 100% 2-hit skelegons, because you would have to be able to sometimes 1-hit guardians as well...

So it's just not possible...