Copy/pasted for those who just want to stay here:
TL;DR: Valkyn set adds about 9.1% overall damage in a Dual Wield/Bow setup in PvE.
4% chance when damging an emey with a damage over time effect to call a *meter* dealing 720.0 Flame damage to target and 360.0 Flame Damage to other nearby enemies.
I've been lucky and picked up two pieces of Valkyn Sorkin's new armor set in medium armor. Crappy traits but, medium armor. What's that mean? Time to teach the baddies of Tamriel the metric system!
I've been keeping track of the stats via CLS and hit aprox 25m damage with this set in PvE. Curious as to how much it adds, I did the math. I didn't add any of the following damage to the final calculations as they're either too tiny, or not part of my normal "rotation", Ambush, Weapon Bash, burning proc, heavy attacks, Synergy attacks, Camo Hunter. Basically things that only begin damage (Ambush) or are rare to use (Heavy attack/Bash/Burning. How the heck DID I get burning?!?)
Testing Methodology
I used the following items: 2pc Valkyn, 5pc Hundings, 2pc Night Mother, 3pc Ravager. Weapon crit hovers between 67 and 75/80ish depending on Haderus buffs and how focused I feel like being on my bars. Since I use this setup in PvP as well, small pieces are impen, large are infused, Valkyn Head/Shoulder is Impen/Reinforced. I hover just under softcap (by about 3 points) on max stamina with this setup and a mere 184 weapon damage. I really should up my weapon damage now that I think about it. Average single target DPS is about 1.2k, every once in a while with trial healers blessing and good procs with Evil hunter I can top 2.2k DPS on the atro in AA. (Pretty much a meter every single second and multiple evil hunter procs. It was glorious, wished I was recording it. Actually I wish I hadn't screwed up my rotation, it would of been higher. ;)
Typical boss fight beings like this: Focused Attacks, Caltrops, Poison Injection, Ambush (if needed to get close) -> Blood Craze, Flurry spam and keep DoTs as needed, pop potions when below 33% stamina. I have Syphoning on 100% of the time and do not use impale during execute (Flurry does more DPS than impale). I drop veil whenever possible, it has about a 2/3 uptime.
Trash Pulls: Focused Attacks, Caltrops the largest group possible, Steel Tornado till they die. Sometimes I pop blood craze on high health trash when im with a poor healer. Very few DoTs in most trash pulls, but with no AoE cap on caltrops the metric system comes raining down quite often. Works best if you have a DK pulling in everything.
**Raw Damage: **
Rapid Strikes: 13,075,251
Steel Tornado: 3,932,573
Razor Caltrops: 2,001,958
Meteor: 2,445,625
Veil of Blades: 1,514,156
Blood Craze Bleed: 1,211,156
Poison Injection: 990,208
Light Attack: 601,229
Blood Craze: 576,521
Befouled Weapon: 266,156
Poisoned Weapon: 97,479
Poisoned: 66,427
Total Damage: 26,778,737
Meter Damage: 2,445,625/26,778,737
Percentage: 9.1%
Overall, I'd say its a really solid set to use. I highly recommend it. I'd expect even higher numbers with a trial DK build as they have more DoTs they regularly apply.