This thread is pertaining to the usage of Scourge in a raid environment. This thread assumes a viper/sinister build with no vitality from gear.
Updated to the new life force costs
Scourge's meta build will presumably be using Soul Reaping with Vital Persistance and Strength of Undeath. Using the chart this gives a life force pool of 16673. This yields the percentage cost of each F skill per use.
F2: 11.61% per use
F3: 14.92% per use
F4: 22.10% per use
F5: 27.63% per use
These numbers can then be combined with their cooldown to get a average life force cost per second value for using the skill on cooldown.
The first percentage is cost without alacrity, the second is with 100% alacrity. The base cooldown accounts for Vital Persistence.
F2: -2.90% -4.33% per sec (4 sec base cd)
F3: -2.33% -3.53% per sec (6.4 sec base cd)
F4: -1.84% -2.74% per sec (12 sec base cd)
F5: -1.72% -2.57% per sec (16 sec base cd)
Scourge's meta weapon sets will presumably be scepter/torch with scepter/dagger.
Feast of Corruption gives 13% (14.3% with Gluttony) life force per use. This yields a life force gain of:
Scepter3: +1.43% +2.13% per sec (10 sec base cd)
This demonstrates that Scourge running double scepter does not generate enough life force to use F5 on cooldown. However according to a recent dev post, Harrowing Wave will now grant 3% LF (3.3% with gluttony). Harrowing Wave has a cooldown of 20 seconds, and while Fell Beacon does reduce the cooldown of Harrowing Wave, due to weapon swap cooldowns Scourge will not be using Harrowing Wave more than once every 20 seconds regardless.
Torch4: +0.17% +0.24% per sec (effective 20 sec cd)
Combined with Scepter3 this yields:
Scepter3 + Torch4: +1.60% +2.37%
So even with Torch4's new life force gain, Scourge cannot get enough life force to use F5 on cooldown.
Scourge will presumably use BiP and Epidemic for utilites. This leaves 1 free slot for a life force generating utility.
I propose using Shadow Fiend as that utility. Shadow Fiend's active skill Haunt generates 10% (11% with gluttony) life force on use. Using Haunt on cd yields the following:
Haunt: +0.55% +0.82% per sec (20 sec base cd)
Combined with Scepter3 and Torch4 this yields:
Scepter3 +Torch4 + Haunt: +2.15% +3.19% per sec
This will allow scourge to use F5 on cd, and maybe one of the other skills every once in a great while. However I'd like to increase my F skill usage as much as possible. I note that not every fight makes use of epidemic, so I prepose using Signet of Undeath in place of epidemic in relevant fights. Signet of Undeath passively generates 2% Life Force every three seconds, which yields a average of:
USiggy: +0.67% per sec (USiggy passive is not affected by alacrity)
Combined with Scepter3, Torch4 and Haunt:
Scepter3 + Torch4 + Haunt + USiggy: +2.82% +3.86% per sec
This still does not allow constant use of anything beyond F5, but it does allow more frequent use of other things.
Other mean to increase LF.
Please correct any bad math you see.
Sanity is for the weak minded