-Invoker, only spells are allowed
-Only a kind of a card on the deck
-Heavy Storm, Flood and Thunderstorm are automatically activated each players turn(This requires help from Zanz, I know)
-Passive Killers, no cards with skill with activation cost allowed
-60-cards war, no rare, no upped, no rainbow
-Fractal war? Your deck must contain 6 Fractal
-Mindreaders, deck must contain Mindgate and Precognition
-Only weapon and shield cards are allowed
-No permanent allowed (maybe allow pillar and pends?)
-Siege war, no permanent allowed except Catapult, and your deck must contain Catapult and Tower Shields?
-One-on-one, players are only allowed to summon 1 creature in the field
This is still growable xD