Hmm... finally a way to make a fractal animate weapon deck?
(mark of air, use arcane mastery to produce animate weapons, use fractal to duplicate your flying weapon = 23 flying weapons
)
Though some cards really need to be excluded... for example granite skin, because it would allow you to increase your max HP infinitely and gain huge rewards.
Miracle should at least have a really low probability of appearing, the same with fractal, and probably some other expensive powerful spells. Maybe make each cards probability inversely proportional to it's cost?