Final answer:
The provided text does not specify who joins Percy on his quest; additional context is necessary to determine the correct answer.
Step-by-step explanation:
The individual who joins Percy on his quest is not explicitly named in the provided text excerpts. These narratives seem to pull from various sources and introduce different characters who interact with a Percy, but without additional context or a reference to a specific story or book, pinpointing who joins Percy on a particular quest is not feasible.
The text excerpts offer characters like John T. Unger and a mention of a character named Kismine, who appears to be in a romantic relationship with John, but no clear connection to Percy's quest is indicated.