The Forces of Destruction seek only to topple civilisation, to shatter the shining cities of the High Elves, burn the towns of the Empire and despoil the Dwarf holds. Where the Forces of Destruction march, they leave only carnage and sorrow in their wake. This should not be taken to mean that the Forces of Destruction are any more a unified alliance than the Forces of Order.
They are just as likely to battle amongst themselves as with a common foe, whether in appeasement of an unholy god, to further some despicable scheme or simply because their boiling blood lusts for constant battle.
The Forces of Destruction are:
Skaven
Warriors of Chaos
Beastmen
Daemons of Chaos
Dark Elves
Vampire Counts
Orcs & Goblins