Cleared Magician Gold!
http://prntscr.com/l51rqg
Not much to say here. The Magician is pretty easy to pick up and play if you're familiar with casters. Due to very precise play with BLUDTUPOWA squeezing me to level 7 and all of Mystera's boons, along with enough money for compression seals and a Mage Plate thanks to Gloves of Midas, I had quite a few resources left over after the boss. A fun little challenge, but it wasn't too difficult. I think I could have made level 8 even, but all my level 8s and 9s were either Animated Armors or Siabrae, neither of which were really possible to kill.
I think it might be a good idea for Mystera to always spawn near the starting point for this challenge, as in Berserker Gold, because if you don't find Mystera early, you probably can't win.