You can't make a good deck w/ All Nightmare? o-0. Jungo too? o-0x2.
Here's my Jungo deck, gets you at least to 1200, and you have 1 star flexibility in case you need to bring in SOA or Stop: X
If you're still can't do it, you might want to sell some of your clans and try new ones.
Here is a deck that will keep u safe from bans and will be good its mono Skeelz.
it's a great deck trust me now for nightmares here is a good ban safe deck.
Glorg (to Oshitsune if he is unbanned)
Askai or Ongh its preference I like Askai better but Ongh takes down Ulu Watu and Bangers
Buba or Greow/Scotty if u r worried about Soa
Odile/Jalil i like Jalil
Wendy/Mindy i like Wendy
For that deck naheema to Askai or Ongh. but Jungo are usually not 1300+ material with out sylth, and not 1400 with out both him and Ongh. But there are exceptions to this (the dude who set the record). Skeelz are a very good clan which can change depending on the abilities you choose. But if you have all of the Jungo, sell Kreen Cr in a few weeks, then buy a clan you like...even if it is Rescue :sigh:
What was the deck that previously got you to 1300? just asking cause it'll help explain your playing style, and you might be able to just switch out the two banned cards
You can try my deck if you've got all the Nightmares, I'm sitting at 1313 and it was a pretty easy trip.
Also, despite what everyone says, Glorg is not that useful in mono Nightmare in my opinion. Replace Oshitsune with Azgaroth next week and you'll be fine.