Reunion

The reunion refers to the point in Golden Sun: The Lost Age when both Felix and Isaac's parties join forces. This event happens in Contigo after the Jupiter Lighthouse episode. After the reunion, many of the game's areas can be revisited to reach places you normally couldn't go to without Psynergy from Golden Sun.

The reunion is the event that the game's Password Data Transfer system revolves around and ends at. Since the reunion is the event where Isaac's party from the original Golden Sun joins your current party in The Lost Age, their inventory and power levels will match what they were in the previous game based on whether Data Transfer has been used in this game file or not. This means any changes to Data Transfer to the file via the Update feature on the main menu has to take place before this event. The Update feature brings you to a screen that identifies which of the save files currently on the cart has been saved after the reunion (as "Post-Reunion Data") and the selectable, updatable files that have been saved before the event.