Curse of Shadow or Curse of Agony?

[Klanlock]

I just got Curse of Shadow, 8% increased shadow dmg and 60 less shadow resistance to the enemy.

Is that damage boost worth not casting Curse of Agony, and rather just cast CoS? I use a Succubus with lash of pain (which does shadow damage) along with all the other stuff. I'm mainly a destro lock (building up to be sm/ruin, already got the ruin part done) so shadow damage is a big part of my dps. Shadow bolt, corruption, shadowburn, death coil, etc...

So would it just be better to cast CoS, or is CoA always the way to go?

[Botmaster5]

if the fight is short, CoA is not mana efficient. myself, since getting CoS, my rotation usually is something lke this:

CoS/CoA > Siphon Life > Corruption > Lifetap > Shadow Bolt till 1/2-ish health > Lifetap x 2 > Drain Life till dead.

if all goes well, my HP will be topped off, and after a final Lifetap after the mob is dead, I should be fairly close to being topped off on mana as well

[koelkast]

if the fight is short, CoA is not mana efficient. myself, since getting CoS, my rotation usually is something lke this:

CoS/CoA > Siphon Life > Corruption > Lifetap > Shadow Bolt till 1/2-ish health > Lifetap x 2 > Drain Life till dead.

if all goes well, my HP will be topped off, and after a final Lifetap after the mob is dead, I should be fairly close to being topped off on mana as well

I dot corruption before Siphon hence to more Nightfall procs and I think siphon aint great on short fights only marginal health gain and damage.

[diogenes]

CoA is not mana efficient.

What are you talking about? CoA is a lock's most mana efficient spell. I suppose maybe you're referring to it not dealing much damage, and its damage increasing as it reaches the end of its duration, but if you mean that, then LITERALY EVERY DOT is not mana efficient. If there's not enough time for the dot to tick, its not worth casting the spell.

However, as you point out, CoA suffers especially bad, as it does very little damage for the first 12-15 seconds (I cannot recall its exact damage increments atm). However, it costs so little mana in comparison to immolate, corruption, and shadowbolt, that its mana efficiency should not be your concern. What your concern should be is "is it worth spending a gcd on this." Even while grinding solo, often times the mob dies well before 12-15 seconds (or at that point) and as such its really not worth using unless you're pulling more than one mob at a time.

As for CoS rank 1 (and really rank 2), you get 8% more shadow damage dealt. That means for every 12.5 shadowbolts you cast, you've effectively done an additonal shadowbolt worth of damage. In otherwords the GCD of CoS (assuming you do not have any points into bane) is worth using when you have cast 6.25 shadow bolts as seen by the equation: (GCD for CoS/SB cast time * x number of casts) =.08 * x number of shadowbolts or (1.5/3x)=.08x. Notice that when you reduce the cast time, the number of shadowbolts actually gets worse: (1.5/2.5x)=.08x means it takes 7.5 shadowbolts for CoS to be worth the GCD cast. Now, I only included shadowbolt in the rotation. When you factor in that immolate does not benefit from CoS and the fact that corruption's cast time is low as well, its easy to see that CoS is not worth it unless the fight lasts a considerable amount of time.

Now the question, whether CoS is worth it or not, all depends on the ranks of the spells you have and how much damage they're doing. I'll answer this specific question when I get home, as it includes more arithmetic than I have time for at the moment. However, hopefully I've given you an idea of the benefit of CoS, and I seriously doubt that it will ever be worth it (over using CoA) when you're the only shadow damage source in the party. But, remember, CoS does have the added caveat of reducing shadow resistance, so if you're noticing that you're getting an unusual amount of partial resists, it is probably beneficial to apply it (as partial resists are a SIGNIFICANT decrease to damage).

[Botmaster5]

CoA is not mana efficient.

What are you talking about? CoA is a lock's most mana efficient spell.

Do not quote me out of context. I clearly said...

If the fight is short, CoA is not mana efficient.

If the fight is less than the duration of Corruption, CoA is not mana efficient. The mana spent casting CoA would be better put to use partially casting another shadowbolt.

[Numi]

But, remember, CoS does have the added caveat of reducing shadow resistance, so if you're noticing that you're getting an unusual amount of partial resists, it is probably beneficial to apply it (as partial resists are a SIGNIFICANT decrease to damage).

DoTs are not supposed to be partially resisted, if that is happening, use the bugtracker and submit a bug report please.

[Bioness]

Usually if the mob is of equal or lower level, placing Curse of Agony, Corruption, and Siphon Life while using Darin Life once or twice will usually kill them. I find this is not the case with Curse of Shadow. When you start getting spell power a single Curse of Agony at full duration can usually take 30-50% of a mobs health. How do you have it go its full duration? Simple, you chain pull while your Voidwalker holds aggro.

I believe there is a thread in the Feenix forums which actually has the calculations of when to use Curse of Agony and Curse of Shadow. I will say however that if the fight will last longer than a minute, throw a Curse of Doom over both of those.