Okay I have not created this army yet. I only have some berserkers, bloodletters and some orks. In this army it is going to be almost composed completely of my own khorne daemons, these daemons are more vicious and animal-like bloodletters to demonstrate the primitive rage of Khornes followers. They are more ape-like and close to the size of gorillas, their attacks are just ferocious leaps followed by savage beatings with their strong arms, hitting with objects (like rocks and sticks etc.) and biting and scratching with nails. Marines who have fought these daemons and lived to tell the tale describe of such ferocity, strength to rip pads of armor from terminators and bloody ravages on Imperial guardsmen.
I made a picture of a chaplain fighting these creatures on computer:

What do you think of the idea?