Astro Knights Eternity: Mystery of Solarus is an extension of the base game, continuing the battle with new elements. 

The expansion introduces a new nemesis, minions, two Astro Knights, and a new homeworld, expanding the universe and storyline. The ongoing battle spans across another system as the Astro Knights strive to protect the universe from impending danger.

- Deckbuilding with no shuffling
- Variable turn order