Blessing of Blackfathom

Blessing of Blackfathom is a debuff you get when you activate the glowing orb on the alter behind Gelihast in Blackfathom Deeps.

While the effects of this are beneficial (grants an extra 10% to all stats and 15% spell damage to Frost spells), it actually takes up a debuff slot on your character.

History
Previously, this debuff increased Intellect and Spirit by 5, and Frost Spell Damage by up to 15. Patch 4.3.0 changed this debuff to be beneficial to all classes. However, unlike its prior version, it is removed upon exiting Blackfathom Deeps.