Thanks for the in-depth feedback! I'll address it parts at a time :D
Firstly the balancing, yeah sadly I didn't have much time to properly balance, I tried to have it be that the 1-cost cards have weaker effects, 2-cost are slightly better and 3-cost are a lot better, but some status effects are inherently better than others just because of their interactions (like how the aggro-stance is probably the best one, the 1 mana difference to normal is actually worth more than the 3 shield points, but also the randomness of the cards means you won't always get a shield card)
Secondly, having different AI use different decks / strategies could be pretty cool, but as each player shares the same deck (to make balancing easier, neither is in a better position card-wise) it might just end up being that it becomes more of a puzzle game, with the player trying to beat the AI at their own strategy. Though in the post-jam update I might add different AI types that are chosen randomly at the start of a match that makes them focus more on specific strategies, as the current AI plays a more general strategy that doesn't let them take full advantage of their cards. As for the AI speed, that's definitely going to be either lowered or given the option to change in the post-jam update.
Lastly, the reason I added all of the "Donian All-Stars" cards and made it a deck without custom cards is to make it so players don't have to create the custom cards if they just want to get into the game. I'm not sure I'll have the time for the post-jam version, but I might add another deck screen that's like "Full Deck", "Aggro-Focus Deck", "Defensive Deck", "Status Deck" or something.
Thanks again for playing, glad you had fun I think!