I really like this game, unfortunately, my wife wasn't nuts about it. So, I developed a simple solo variant that sort of acts as a game timer. It's not the same as playing against human opponent(s), but if you like the game, this will at least act as sort of a sparring partner for you. Solo variant posted at Res Arcana's BGG page in the Files section. The file is called "Invisible Mage".
I'm really curious for Res Arcana. I only didn't buy it for lack of a solo mode. Thanks for reminding me of your variant. I'll look into this game again.