Grimoire of Service is a warlock talent available at level 75. It summons a temporary second demon to fight for the warlock, but it is not under the warlock's direct control.
Patch changes Edit
- Patch 6.1.0 (24-Feb-2015): Grimoire of Service now summons a second demon for 25 seconds (up from 20 seconds).
- Patch 5.0.4 (28-August-2012): Added.