Most corruption decks have to be able to add 8-10 burdens without trying and 12-14 burdens with some luck and 16+ if you see every card in the deck. For example, my movie block
-
corruption deck will add 8 easily , 12-14 with a little luck, and 18+ if I can cycle through the entire deck.
So witchkings deck could easily add 20+ burdens, if he was playing an opponent who flooded the twilight pool and was pretty lucky to boot. but with the wrong draws or any type of hobbit or choke deck, there's no way he'd get more than 5-6, which brings us to the issue of balance and cycling, not to digress but he's already got 21-24 cards and none of them draw or discard, no cycling, plus he has only 4 nazgul which means he'll need at least 10-12 more, bringing the total up to at least 31, possibly ballooning up to 35/36, with most of the cards being high cost (The nazzies,
BNAP,
Keening wail) and no cyclin cards. In fact, the skulkers at that point would hurt not help as they would put more cards back in the deck. So costly minions, no cycling, and a high card count, I think it would be hard for any deck like that to function well.