Complex sentence: Jess's old compy EA that had been passed down to him from Ross was gifted to his sister Tasia, whom Jess had taught to pilot a few types of Roamer craft and they sometimes went out looking for the lost generation ship Burton.
Split into simpler sentences: Jess's old company EA that had been passed down to him from Ross, was gifted to his sister Tasia, whom Jess had taught to pilot a few types of Roamer craft. They sometimes went out looking for the lost generation ship Burton.