i wish this existed
a magic the gathering engine + evolution algorithm to develop and playtest duel decks that were perfectly balanced, variable, and fun.
i don't want to spend my time reading through all the cards and playtesting with myself before printing some new decks to play with my friends, and i don't want to use online decklists because they're typically too competitive (filled with 4x of the best cards) and repetitive to play.
as i understand it, this would be very hard to make. writing an engine for mtg is very, very complicated, and writing an AI that could play it would possibly be even harder (especially if you wanted to adjust its intelligence to simulate professional versus kitchen table play)
but assuming that the cost of programming R&D is going to fall off a cliff, maybe it will be possible in the future. i would love to see it (and more generally, auto-balancing in all games) happen!