To help fill new players in on the Golden Sun lore, and to help returning players remember the people, places, and events from those GBA games, the dialogue in Dark Dawn is peppered with links like the one above (the "Tap!" graphic is there because that was the first such link to appear). Tap and an encyclopedia entry for that entity appears on the top screen. It's also saved so you can go back through them later. Who were the Warriors of Vale? What's a Sol Sanctum? The game is free to refer back to this stuff, secure in the knowledge that you can figure it all out.
Now that it's been done, all games with lots of characters, or lots of backstory, should implement this immedlately.