You can have a unit of 20 chosen, all of whom are upgraded to champions in terminator armour of tzeentch, toting a powerweapon and a powerfist and deamonic mutation (thats 5 attacks each) which makes for 120 attacks on the charge.
Then each one can have 4 chaos hounds so thats an extra 240 attacks on the charge
Then each one can have a chaos spawn as well for an extra 20D6+20 attacks on the charge
Then each one can have 4 thrall wizards as well as that for an extra 160 attacks on the charge
So how does 540+20D6 attacks grab you?
Plus of course if you give all the chosen the psychic power that turns models into spawn you can add more chaos spawn to the unit for even more attacks.
Of course, this is ridiclous and totally silly. But it is allowed.
(ps. I'm sorry
)