I first tried using the skill casting tab in Mafia's interface. Then, when that didn't work, tried manually in the relay browser. Then, did the debug when the second method failed, using the mafia skill casting again. So yeah, the skill was showing up in both the mafia and browser skill lists. But apparently, KOL didn't want me to use it that night. Afterward, I shut down the computer for the night, and the next day, was able to use the skill normally again, as if the weirdness hadn't happened. I had gotten out of ronin that night, so I wonder if perhaps that caused some sort of oddity? I've gotten into the habit of exiting mafia and re-logging in after exiting ronin, due to the skills weirdness mafia has with that.