So i found this out by a misstake, not sure if its posted or not, but anyways
So if your A warlock with the talent "Grimoire Of supremacy" it will turn your demos into stronger ones and infernal (Abyssal) does not aggro guards when used and has a passive aoe.
#1 find a low level
#2 summon abyssal ontop of him
#3 the aoe will kill him
#4 sit on your flymount rofling
#5 ??
#6 profit.
not sure if it works everywere, but it does work with shadow-pan guards killing level 86-88s my pet scaling from my heroic raiding gear.