What it does:
1. It deals damage every 1/3 of a second. or 1/2 of a second, I'm not so sure. So it is also INDEPENDENT of your ATTACK SPEED. Hence, even with 3 APS, it would still do a constant stream of damage per second.
2. It does indead proc LIFESTEAL. However, it does not SNAPSHOT Gloom.
3. It procs EVERYTHING you can proc EXCEPT Critical Hit
Other notable things it procs:
Marked For Death - Mortal Enemy
4. DOES NOT Reflect Damage(more tests on these but im 99% sure of this since its a SENTRY)
5. It deals damage on a SMALL RADIUS around it and somewhere along the lines of the Chains. and not just on the chains itself. a SMALL RADIUS around you and the Sentry itself too. Much like it radiates an aura, though small. You can see how it works.
6. Since it doesn't CRIT, it takes its damage factor primarily on:
- pure Damage - min/max
So Rubies will help MORE than Emeralds.
7. Although it is independent of your APS, Calamity/Windforce "might" work better on lower end of weapons since it has Min/Max damage(BLACK DAMAGE) wherein the Skill takes it damage from.
However, if a Manitcore is gemmed with Ruby, it will deal higher damage. NEEDS MORE TESTS though.
8. The skill needs a whole lot of positioning to work with to its full potential though.
Synergy with skills/procs:
Marked for Death- Mortal Enemy
The skill works so well with this that it's amazing. Just mark an enemy, put down those Chains and then position accordingly. You'd get 3 Hatred every time it ticks for damage PER sentry you placed and hits the Marked enemy
The skill procs WF's KB potential too. If you want to test it out, just rune for it. Go place a few and let the enemy walk towards you.
Know those Savage Beasts in Act 1 that many hates? They can be KB'ed mid-charge with WF and CoT >_< Saved me a whole lot of times.
Same thing, it procs it at a nice rate too. If in a 1on1 battle with an elite/champ, it will make it so that the target is Marked PERMANENTLY.
Items you have that has "Chance to"
Freeze, Bleeding, Slow, Immobilize, ANYTHING. Even LIFE on HIT is taken into consideration.
Want to continually SLOW enemies but all your skills aren't able to proc it? Well.. CoT will proc SoJ's Cold if it hits an enemy. So you can use that CtW passive to your liking without any sacrifice in your other skills.
Shadow Power- Gloom or 25% LS.
Like I said, it retains the LIFE STEAL aspect but DOES NOT snapshot it. Still, a 5second bonus LS is useful >_< With 28k constant damage on 1 Sentry, that's 1k+ LS per tick. Put 3 down with Costum Engineering and if those 3 hits, 3k free LS :)
Archery - Bow
It benefits on this too since its a direct increase in damage dealt.
Works with it too but it doesn't snapshot the bonus damage meaning if a mob goes near you and changes your DPS, the damage it deals also changes.
Works best with:
Any spec that delves on TANKING stuff
WF Users that wants an additional source of Knockback.
WF + Steady Aim works with it too.
Any spec that works/delves with ON HIT effects.
So far.. that'll be all. Hope this helps other people. Will update further later ^_^