Curse of Shadow

Curse of Shadow, or CoS for short, was a Warlock Curse that makes a target more susceptible to Arcane and Shadow damage and spells. Its function has been replaced by Curse of the Elements.

Talent improvement
Malediction increases the damage bonus effect.

Suppression reduces the target's chance to resist.

Grim Reach increases the range to 33/36 yds.

Improved Drain Soul reduces generated threat.

Tips and tactics
This spell was always used before using Enslave Demon to increase the effectiveness of the enslave. The demon was less likely to resist, and the curse remained in effect while the demon is enslaved, decreasing the chance that it wwould break the enslave early.

Used together with DD spells like Shadow Bolt, as well as to aid Mage or Druid characters that use Arcane, or Shadow Priests that use Shadow Magic.

The Voidwalker's Torment is Shadow-based, so this helped the voidwalker to hold aggro.

It was helpful on raid bosses when you have multiple people attacking with Shadow and/or Arcane spells.