Star Trek: Stargazer
Karn Zax is a known Cardassian mercenary. He’ll work for anyone with enough latinum to pay his rather outrageous fees. It’s not that he’s good, he’s just willing to take on seriously bad jobs. He has lived through several of these near suicide missions, the same cannot be said for his people. Typically Zax will hire new operatives for each job. This way any that die in the process of finishing the mission will have their possible payment default back to Zax. Zax rarely rehires previous operatives for fear they will scare the other suckers.
In The Graduates, the job seemed rather easy. Zax was chosen because he can keep his mouth shut after a job. However, what his intell told him were deflectors on Harga1 turned out to be shield emitters. In this case, a dangerous and something of a fatal mistake.
Zax, using Ralic’s money, purchased some old Ferengi corvettes. Frankly calling them that was flattery. They were over powered, warp capable gun ships. Even with that, Stargazer was able to kill one and force the other two to flee.
Zax appeared in The Hunt for Kine-Uthra-Klul, but he simply refused a job for not paying enough, then helped the crew of Stargazer get the job.
If there is a dangerous job with a giant pay-out, Zax will likely appear again.