I play several card games and i hate to say but the deck and deck building screen definitely needs some work on the UI, currently feels worse than the others.
here's some criticism-
-when editing an imported deck, numbers show red if you do not own the card, but does not show how many you do own. (have to right click each one to see. it's probably tricky to implement and is only bad if i barely own any cards)
-when editing a deck, there is no way to jump to a selected card in your deck (hard to explain but in HS, right clicking the card does this). this compounded with the above means that
-for imported decks i have to type and search for every card i do not own; if i want to increase the count of a card i my deck but do not own additional copies, i cannot up the count of it and have the color be red. Similarly, if the number is red 3, but i own 2 copies, and i subtract a card, then try to add it back, it won't let me go back to red 3, and stays at white 2.
-In short the above point really just means, i can't create an invalid deck with cards i don't own, only import it.
-no "craft all / craft remaining" button
-no way to rearrange the deck order.
-no way to change deck image
-no duplicate deck option
-Viewing all owned wildcards is only on the Store tab. Would make sense if collection tab had this as well.
-Minor issue: The "Ashe" deck for day 7 i believe is not a deck, it's just like, 5 cards i think? It creates a deck for you but does not actually give you the cards, it fills with what you own. What ended up happening to me is that the deck is invalid cuz i didn't have 2 copies of Grasp of the Undying. that could confuse people since the reward said 'new deck'.
Hope this helps.
P.S. Game is great and honestly, UI is quite good given that it's just been released.