The Imperial scout is seen here utilizing the key crystal.
The key crystal represented a Seoularian crystal with the capability to govern all other crystals of its kind. It was directly influenced by psionic abilities and could generate progressively powerful shockwaves. Shortly prior to the commencement of the Galactic Civil War, an Imperial scout came across the planet Seoul 5 and extracted the key crystal from the Crystal control room. Ultimately, he relinquished possession of the crystal to Han Solo in a card game; Solo then returned the key crystal to Seoul 5. Solo employed the crystal to overcome Imperial Adjutant Ssssk!, but subsequently, he unintentionally triggered an overload in the remaining Seoularian crystals. In his haste to flee the impending cataclysm, Solo abandoned the key crystal, which was then obliterated in the subsequent detonation.