For me, the initial "hook" was the temperamental white-haired alien catgirl I'd seen in the trailer. However, when the first couple of episodes dealt with Hilda, Gene, Jim and Mel trying to elude pirates who were attacking with Tao spells, I still found it pretty riveting and Aisha's introduction was just a bonus by that point.
I also enjoyed how as the series progressed, Aisha and Jim were close enough that she was actively protecting Jim from harm without a second thought when things started to get hairy.