One of the commanders 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 despised these 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 the Zefra by the Naturia Sacred Tree, and fused with the other chosen, becoming Zefraath. With this new power, he fought Tierra for 1000 days and nights and destroyed her, freeing the world from the control of the goddesses.

Tier: High 4-C |High 4-C |High 4-C |High 4-C |High 4-C

Classification: Level 7 Earth Attribute Rock Type Monster |Level 8 Earth Attribute Rock Type Monster |Level 7 Earth Attribute Thunder Type Monster |Level 4 Dark Attribute Rock Type Monster |Level 11 Earth Attribute Rock Type Monster

Powers and Abilities: Superhuman physical characteristics, fusionism (All Gem-Knights are capable of fusing with others to becoming stronger and gain new abilities), martial arts (Skilled in hand to hand combat), flight|Superhuman physical characteristics, martial arts, 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 (Vylon are able to sense traces of evil in others), light manipulation, resistance to corruption, body puppetry, soul manipulation, technology manipulation, disease manipulation, possession, empathic manipulation, and mind manipulation (Shares the Vylon's resistance to the effects of the Steelswarm and Evilswarm)|All previous powers to a much greater extent plus light manipulation, and darkness manipulation |All previous powers to a much greater extent plus large size (Type 3), ice manipulation, resurrection, power bestowal, life manipulation, soul manipulation, power nullification, attack reflection, telepathy, biological manipulation, healing, possession, empathic manipulation, and absorption, sealing, mind manipulation, corruption, existence erasure, animal manipulation, immorality (Type 5. Exists unbound from the Cycle of Reincarnation, which is the cycle of life and death due to gaining Zefraxion's powers), adaptation, reactive evolution, weapon mastery (Skilled swordsman), summoning, water manipulation, fire manipulation, earth manipulation, air manipulation, darkness manipulation, illusion creation, electricity manipulation, resistance to corruption, existence erasure, attack reflection, and power nullification

Attack Potency: Large Star level (Should be comparable to Gem-Knight Pearl. The Pyroxene of each Gem-Knight is a fragment of the Core of the World Tree, and each Pyroxene is powerful enough to create a Yang Zing)|Large Star level (Much stronger than his previous form, described as the maximum optimization of his abilities and the absolute limit of his power)|Large Star level (Much stronger than his previous form due to wielding the combined power of Gem-Knight Crystal and Vylon Prism)|Large Star level (As one of the Ten Chosen Zefra, Zefracore was amplified by the Naturia Sacred Tree to the point that it could fight El Shaddoll Anoyatyllis alongside the other ten Zefra warriors)|Large Star level (Immensely more powerful due to having the combined of all ten Zefra warriors as well as all of the Yang Zing. The only monster capable of fighting Purushaddoll Aeon Tierra which reduced the Naturia Sacred Tree to ashes)

Speed: Unknown |Unknown |Massively FTL+ (Comparable to Steelswarm Roach and constellars)|Massively FTL+|Massively FTL+

Lifting Strength: Unknown |Unknown |Unknown |Unknown |Unknown

Striking Strength: Large Star level |Large Star level|Large Star level |Large Star level |Large Star level

Durability: Large Star level |Large Star level |Large Star level |Large Star level |Large Star level

Stamina: High|High (Fought Tierra for 1000 days and 1000 nights without rest)

Range: At least Kilometers |Planetary

Standard Equipment: Pyroxene

Intelligence: Unknown

Weakness: None notable