Warlock Passive Skill

Description: Attack rate increased when 'bard' is summoned.

Condition: Add 12 Skill Points

1 2 3 4
Required Skill Points 2 2 2 3
Attack Increase 10.0% 14.0% 18.0% 24.0%

As the statistics suggest, Bard of Destruction increases Attack, not Attack rate. And in reality, this is an overall damage buff - all damage is increased (bar Pain Overture, which is considered to be inflicted by an enemy).