It would be nice if duplicate cards stacked on top of each-other when they are not in a deck as it is rather easy to miss a card when there are so many all spread out one by one,
or at least an option to allow something like this.
Main issue I have so far is the darned Conjuerer, once you hit a high enough level you never bother summoning anything as you auto attack for about five times what the pet would hit for.
Maybe make them stay from fight to fight so they don't need to be recast every battle?