The Soul Bound Saga tells the story of a group of demi-gods who protected the Athensphere against Gazia.
Each demi-god can be evolved and their materials are available to their respective vortex.
If you want to know more about them, click the images below.
Note: The Soul Bound Saga Vortex Dungeon are permanently available. For details on permanent events currently in the game check the article here.