I know it is a silly question, but does WKL increase the damage of lightning skills only, or does it increase the damage on skills that do lightning damage because of "add x% to lightning ". I mean, if i use a skill that does weapon damage, and i have a black weapon main hand and a WKL offhan, it will do lightning damage on that skill, is that damage increased too or the skill needs to previously do lightning damage regardless of "add x% lightning damage" ?
"Adds (X)% to Lightning Damage" will add extra weapon damage to the non-elemental damage part of any weapon you have equipped.
"Lightning skills deal (X)% more damage" will add extra damage to skills that cause lightning elemental damage.
So for your example the black weapon will benefit from "Adds (X)% to Lightning Damage", no matter what element type the skill used was.
If the skill used is lightning it will only benefit from "Lightning skills deal (X)% more damage" as it only affects skills.
So i cant benefit from the "Lightning Skills dead (X)% more damage ", even if the skill is actually doing lightning damage instead of black damage? I mean, only Fist of Thunder, Sweeping Wind - Cyclone, And Deadly Reach - Scattering Blow can benefit from this stat of the weapon ???
The "Adds x% to lightning damage" simply boost the non elemental dmg of your weapon.
F.e You have a Weapon with 100-200 Dmg Range and 1.0aps = 150dps
Equiping a WKL with 6% will result in havin 106-212 = 159dps
The added damage does not benefit from "lightning skills dealing x% more damage". Those are just the ones you mentioned. No the less is a wkl a realy good weapon for monks. A large portion of our dmg is off of those lightning based skills. I would say for lower budgets (sub 200mil) nothing realy can beat a dw wkl setup in terms of edps. No matter if you use palm, cyclone strike or bells as your main spirit spenders.
Most damage on bells you will get from 2hander(skorn or very rare to find rare 2handed axe better then skorn ),but with 2hander setup you have choice to go druin's TR/bell Mp10 build(need decent damage mitigation/all resist) or go for TR/Bell stun build(high HP/high crit hit chance,mostly suited for solo play)if you wanna go MP10. WKL is only good for %damage on lightning skills(SW-cyclone and fist of thunder-thunderclap),and you want 24-25% as optimal. If you have budget you can increase SW damage even further with inna's radiance(up to 14% damage increase on SW),mara's kaleodoscope is amulet with up to +12% SW damage(gonna have decent crit hit chance and crit damage too,but expensive),also SoJ with up to +12% or skull grasp with up to 12%(must have crit hit chance with it).This is just more option to boost SW damage even more if you have WKL(in particular if you use cookie cuter build).