I swear there is something messed up with his Dodge system. I am fighting Lokarr now with Chillwhisper full set and he owns almost everything except certain bosses. He just cannot survive against Lokarr.
I feel his Dodge isn’t doing anything useful. Toggles that give Damage Mitigation are way better than his Dodge.
What’s going on here??
Dodge is not damage reduction, but chance to avoid an attack. 20% chance to dodge might be 100% damage reduction for 12 hits in a row, for 12 hits in general or for nothing at all. It’s all RNG, something you should not depend on. Dodge mechanics are mere additions for your build which might be useful if your build is tanky and you want to make it tankier. On squishy builds, dodge is a noob trap that doesn’t increase your defense, but makes you even squishier because you always depend on dodging an attack and it might not even happen, therefore you make stupid mistakes.
It would really help if you upload the build to grimtools, otherwise your point is kinda moot.
Dodge is more of melee build thing. But you still need to combine it with DA, Fumble, Life Steal and damage reduction.
For chillwhisper, unless DE build, just run 
Something I think is worth mentioning is a lot (but not all) of Nightblade’s damage mitigation via mastery skills comes from Veil of Shadow, Shadow Dance and Circle of Slaughter - so OA shred, Dodge/Deflect and Fumble.
While Nightblade does get multiple layers, they’re not 100% consistent compared to other masteries that get defenses that last permanently (e.g. Maiven’s Sphere, Possession, Primal Bond, Censure) or last a specified duration (e.g. Ascension, Overguard).
I chose Nightblade / Necro for the Chillwhisper set. Neither of them have the standard mitigation. I have no problem with most of the content but I feel my Nightblade isn’t dodging anything and I didn’t know Harbringer’s LIfe leeching doesn’t add to Drain Essence. ugh.
oh…how do I do that?
Click on arrow up button in the upper left corner https://www.grimtools.com/calc/
I made a video guide about it https://www.youtube.com/watch?v=fEASwrQ5C7k xD
I found the character fold but the info is a bit older. I made some major changes this morning.
It should still be accurate since it saves to that folder.
Oh. I made a mistake. Yes, it is up to date now! here is the link:
https://www.grimtools.com/calc/a2EbPgjV
The problem is I simply can’t stand still against Lokarr. I just die too quick or not leeching enough.
The change is that now when you click the “arrow up icon” GrimTools will help you with the search path 
For Lokarr , bad armor and phys res.
For Lokarr, big issues that stand out immediately to me are low armour/armour absorption/physical resistance and not high enough DA.
but how do you get more “armor” if I am using Chillwhisper set?
This might give you some ideas [1.1.4.0] Chillheart Devotee - DW Caster Chillwhisper/Proc Infiltrator - 6min [c+][sr+][g3][vid]
Getting more armour is going to be difficult but you can at least push your armour absorption up to 95%+ with a few Scaled Hide/Sacred Plating/Living Armour.
You might be able to pick up a bit more Physical resistance in devotion or by shifting gear around (10-15% is nice to have on casters) but it’s going to be fiddly. Your devotion route could be improved I’d say as I would not go for Will of Rattosh on Gravechill Reaper.
The other thing you should really be looking at as a caster are other ways to lower or mitigate damage that you have not taken e.g. Mark of Torment and Decay/Ill Omen.
Edit: Getting a better relic than Deathchill would also help a metric ton, Serenity would give you a circuit breaker and help with capping resistances for instance.
Everything Evil_Baka said should be done immediately. Both Mark of Torment and Ill Omen are a must and Will of Rattosh just isn’t helping you. Try and change your gameplan. I would have taken Rhowan’s Crown and Murmur and focused completely on cold damage. Frostburn alone should be enough to take him down but you need to make a lot of changes gear-wise.
Amulet - You need a “Mythical Deathbound Amethyst” - can’t get one, use what you have but know that it’s definitely not BiS for your build
Belt - Farm a “Gargoyle Waistguard” - A decent one will improve your build exponentially.
I get you tried a bit of vitality+cold but in the end those type of builds will not be able to take down a celestial. It’s easier to focus on one damage type.
Lokarr has 105% Vitality damage and 35% life leech resistance, keep that in mind.
He can easily one shot you in your current setup.
What others suggested is totally valid, but that’s a fundamental problem with this set. DE wants you to facetank, but Chillwhisper just lacks that capability, especially if it’s Reaper rather than Apostate. Most common way to use this set for high end content is to just kite while Blade Spirits do the work.
I took Rattosh thinking that I can out heal his damage as the -health resistance seems useful on my other Drainer.
So I should focus on Cold/Frost damage instead eh? I try to go with a mix of Cold/Vitality but I find that some enemies are very resistant to Cold.
And I also hate using Mark of Torment. I find it’s a very buggy skill. Many times I use it, it doesn’t come out right away. And it only lasts like 3s?? ugh.
Thanks. I’ll read through all comments again. I picked this set because I really like Drain Essence, thinking that Blade Spirit can help me leech more health. LOL
I thought about Deathbound Amethyst but didn’t take it because I don’t like how it changes everything to Cold but I get the point now.