Well, looks like Oshitsune's banned for now One decision made for you. Aside from the Artus change it's fine. There's no need to put more stars on the Nightmare side. Their higher star count cards are comparitively weaker than those from Ulu Watu.
Hmm I have the feeling that some other health builds could be a little more damaging though, but this deck is a good setup for that goal, it just needs more reducing, soa, stuff to stop them from coming back in or at least more separation in the matches. Chel seems neat though Kenny Cr can be tough to use because of low power especially without clan bonus, hmm, I wonder about skeelz? Or maybe jungo