For Mustadio, concentrate w/ a Priest or a Time Mage increasing his chances of survival. Other than a couple healers, throw in long range killers like a Ninja or a Summoner. And that's if you're going to "Save Mustadio". If you're not, I suggest making an all attack force, regardless of range. And yes, there are the worries of future Zodiac bosses. The first time a saw the second one, I thought I was dead.

Anyways, continue to kill n' train jobs.