1) Magic weakness. Bet you the god killer deck kills this in the snap of a finger.
2) Expense. I dont want to IMAGINE the cost.
3) Card Variety. It's hard to get the card you want out; Example the poseidon would save you life instantly in your battle situation, but your odds: 1 out of 40.
4) Quantum. Quantum Tower are messy. Put EXACT towers, please. Same with god killer deck.
5) The Bottom Poseidon. What if the Poseidon lies at the BOTTOM of your deck? *Blows the whistle* "Team Rainbow has scored a goal!!!" Say goodnight :(
6) Decks with high permanent controls. What if, what if, you battled a player with:
Butterfly Effects (Upgraded)+
Other fire stuff?
You are gonna have a hard time; Steals, Deflags,Explosions,Destroy skills. You only have 3 permanent control, so you WILL be dead here. Seism is a nightmare for this deck, too.
7) Only 5 creature control. What if your fallen druids, ulitharids, and maxwell's demon died off? R.I.P. Guy-Who-Used-The-Devil-Deck, 2014-2014.