Demonology

Demons are leeches of the living universe by their very own nature. The Demonology Warlock mastered harnessing the power of these malefic beings for his or her own advantage in the field of battle. Warlocks harvest the souls of their enemies, and those specialized in the ways of demonology use this life essence to tap into the void and pull all manner of abominating creatures from the chaos of the Twisting Nether. While this practice is often considered by outsiders to be reckless, the demonologist maintains absolute control over his summoned Demons, empowered and beholden to the will of the Warlock.

 

An extremely useful tool for overall optimization

http://www.askmrrobot.com

WoWhead Demonology guide

http://www.wowhead.com/demonology-warlock-guide

Icy Veins Demonology guide

https://www.icy-veins.com/wow/demonology-warlock-pve-dps-guide

Noxxic Demonology guide

http://www.noxxic.com/wow/pve/warlock/demonology/