Which do you choose Curse of Agony or Curse of the Elements or Curse of Doom?
Agony does damage.. but Elements increases your damage and the rest of your raid’s damage. BUT Elements shares a debuff slot with “Earth and Moon” cast by Boomkins (should be part of their DPS rotation) and with “Ebon Plaguebringer” cast by Unholy Deathknights (passive part of their rotation).
Simulation 1: 56/00/15 with Felhunter. 13% spell power is provided by another person in the raid. I cast CoA.
Simulation 2: 56/00/15 with Felhunter. 13% spell power is provided by another person in the raid. I cast CoD instead.
Simulation 3: 56/00/15 with Felhunter. 13% is not provided to the raid. I cast CoA. (no one covers 13%)
Simulation 4: 56/00/15 with Felhunter. I cast CotEl to cover the 13% Spellpower.
Conclusion: If I have a Boomkin or an Unholy DK in my group giving the 13% then I should cast CoA. Otherwise I should cast CotEl. If I think the Boomkin or DK will not be on my target then I should use CotEl.