Assuming that the effect occurs on 2% of spells cast, and the spells are cast once every three seconds, the extra damage per spell of this aura would be 1.96, or roughly 0.653 per second. The negligible damage output renders Dark magic rather useless.
It is activated for 1 hour and has a cooldown time of 3 hours. As with all auras, if the account using it is logged out while the aura is activated, the timer will continue to run out.
The effect of this aura can be likened to poison for magic spells; it does not work on monsters immune to poison, such as Ganodermic beasts, Mithril dragons and Glacors - the most common mage targets with a sufficient amount of life points to warrant the use of this aura. It is currently unknown if the corruption damage from this aura stacks with the real poison damage that comes from the Smoke spells that can be used through the Ancient Magicks. This combination may be useful to damage an enemy in the long term without actually remaining to kill them. The damage done is always 98, always comes in the four aforementioned hitsplats, and takes effect shortly after the hit on which the effect occurred. A yellow message appears in the chatbox indicating that the Aura effect has taken place. In PvP situations, the player being attacked also receives a message in their chatbox.