The best thing to run with shuppet is- shuppet!
Used to be a pretty good deck. Runs shuppets, uxie, and dunsparce from HS (has the same attack for 10 less). Basically, it used Exp belt, and 4 plus power. You attach it all, and hit for 30 + 20 + 40 = 90 total. then back to the hand with it all, to rinse and repeat for next turn. Dunsparce is the same thing, but for 10 less damage. He's just a tech for garchomp, flygon, or anything resistant to psychic. Uxie is good to set yourself up, and can attack with a similar attack. It can also be level X'd for more draw power, and for another backup attacker if needed.
It used to be ran with Mr. Mime from MT, because he would be a good wall to stall with for a turn. But since he's rotated, it might be hard to find another good wall staller- you know, something that prevents them from attacking you. Also, spiritomb/vileplume decks will shut this down, since you cant play your tools down.
A good wall, next set, might be Cubone/marrowak. You can use the banette from PL to discard marrowaks from your hand, or you could use Blissey from PL to do the same, but heal cubone. Cubone reduces all damage done to him by 20 for each discarded marrowak. so get 4 in there, reduce by 80, plus 20 more for each defender on him, if you decided to run those. Its complicated, and a lot of stuff, but it could be funny. Just a thought.
I think all and all, this is still a viable deck, if you can get it set up right. But for it to be good in the current meta, you need to do 2 things:
-Find a REALLY good wall/staller to send up after fade-out
-Find a way to counter, or at least work around, trainer lock, which is BIG now with vileplume.
Find an answer for those two things, and you've got yourself a hilariously fun deck. Good luck.