I suggest a new game mode:
1. There are a set of war-decks (arsenal) for each element (50% in-element, limited number of upgrades 3-9 difficulty choice ?)
2. The player has to use a war-legal deck and pick and opponent element.
3. The player plays against the AI which uses a random deck from the arsenal of the picked opponent element.
4. Whenever the player wins, his/her deck automatically enters the arsenal of the majority element of player's deck.
5. The system keeps track of the win-loss record of decks in arsenal and drops the worst performing ones (similarly to arena).
The score-matrix of the War (win-loss of any two elements) can be displayed. The score table could be reset regularly, e.g. once a month.
So its a War-PVP event meets Arena idea, where players play against the AI, but the decks of the AI come from the more successful player-build decks.
