One of the commander of the Gem-Knight faction, Gem-Knight Crystal is one of the greatest if not the greatest warrior of the Gem-knights. Known for his incredible power and fusion mastery, as well as his solidarity, he fought in the Second Great War against the Steelswarm. However, after the defeat of the demons, Gishki Noellia began slaughtering the Gusto tribe with poisonous winds that killed most of the tribe. The Gem-knights, who despise those barbaric actions were thrown into a rage allowing the evilswarm to break loose. With the advent of a new threat, Crystal and his high-ranked allies were forced to fuse together to become Gem-Knight Master diamond,who easily slaughtered most of the Lswarm demons before sacrificing himself to grant Gem-Knight Lazuli the power necessary for a ultimate fusion in order to stop Sophia, Goddess of Rebirth. However, he was eventually resurrected into a corrupted version of himself by the goddess Tierra before being released by the efforts of the allied forces during the Third Great War.He was eventually given the power of Zefra by the natural Sacred Tree, and fused with the other chosen,becoming Zefraath. With the new power he fought Tierra for 1000 days and nights and destroyed her, freeing the world from the control of the goddess.

Classification: Level 7 Earth Attribute Rock Type Monster

Powers and Abilities: Superhuman Physical  Characteristic, fusionism(All gem knights are capable of fusing with others to become stronger and gain new abilities), martial arts,flight, fusionism(has lost all special abilities), all previous abilities to a much greater extent plus weapon mastery(Skilled lance and shield wielder), sealing(Vylon are capable of sealing beings such as the steelswarm), enhanced senses, light manipulation, technology manipulation, disease manipulation, possession, empathic manipulation and mind manipulation, darkness manipulation

Attack Potency: Large Star level

Speed: Unknown

Lifting Strength: Unknown

Striking Strength: Large Star Class

Durability; Large Star Level

Stamina: High

Range: At least kilometers

Standard Equipment: Pyroxene

Intelligence: Unknown

Weakness: None notable