Hello there! I saw MoP talents on wowhead and i noticed that there is a warlock talent named Grimoire of Supremancy which enhances your demon.
Imp - Fel Imp
Voidwalker - Voidlord
Succubi - Shivan
Felhunter - Beholder
Felguard - Terrorguard
???? - Abyssal
source: http://www.wowhead.com/mists-of-pand...t-calculator#o