Sugilite

Sugilite is a fusion character who appears in "Coach Steven." Sugilite is created when Garnet and Amethyst dance to synchronize and fuse together.

Appearance
Sugilite is humongous; at least two times as tall as the fusion gem Opal. Her skin color is a slightly darker purple than Amethyst's and she wears a ripped, dark purple and black costume similar to Garnet's body suit. She possesses four arms like Opal and wears a visor to cover her lower four eyes while her fifth eye is located above her brow. She possesses a giant plume of spiky, dark purple hair. Her eyes tinge red when she's angry. She has a gem on her chest and two sugilite gemstones on each hand on her lower pair of arms.

Personality
Sugilite combines Garnet's headstrong, unwavering nature with Amethyst's recklessness and immense free will. Even when first fused, Sugilite thinks of herself not as a fusion between two personalities, but as a single, complete individual. The mere assertion that she should separate has caused Sugilite to go into a fury.

Sugilite cares for herself, first and foremost. Though she will carry out mission objectives, she will not do anything that she does not want to do, and will not hesitate to use force to get what she wants. This has caused at least one dangerous situation, wherein Sugilite, enraged that she was left behind during a mission and asked to split up, nearly killed Pearl.

Abilities
An absolute juggernaut in combat, Sugilite uses her sheer strength and size to overpower and crush any opposition. Her weapon is an enormous flail that uses Amethyst's whip for the rope, and Garnet's fused gauntlets as the bludgeon. Using this weapon, Sugilite can easily smash through buildings, reducing a defunct Gem communications station to rubble.

Though not as acrobatic as Opal, Sugilite is surprisingly nimble; being able to leap dozens (if not hundreds) of feet in the air and having a running speed nearly that of Pearl's. It is not known if Sugilite has any apparent weaknesses, only being defeated when she was hit on the head by her own flail, knocking her out and separating her into Garnet and Amythest.

Trivia

 * In gemstone mythoi, sugilite stones are known to be gems that balance the mind and soul and serves as protection from anger and negative feelings; which is ironic given Sugilite's dangerous and unstable nature.
 * Like Steven, her gemstone is not a birthstone.
 * Sugilite bears a striking resemblance to Roy Koopa from the Super Mario Bros. Series.
 * Sugilite could also be based on an Oni, a Japanese demon or ogre, due to the gem being first discovered in Japan by Professor Ken-ichi Sugi.
 * She also strongly resembles the Hindu goddess Kali. Kali is often portrayed as having four arms and a very destructive nature. Sugilite's long and somewhat wild-looking dark hair resembles common portrayals of Kali as well. While Kali is usually described as violent, she's still often seen as a destroyer of evil and some legends even show her to have a caring, maternal side.
 * Sugilite shows in the episode "Coach Steven" that if multiple gems are fused for too long, they can slowly lose their individuality.
 * Sugilite also seems to have sugilite gemstones as fingernails faceted in different shapes. The index is shaped as a star while the rest appear to be square.
 * Sugilite is the largest character to be revealed in the show so far, about two times taller than Opal.
 * Sugilite consists of mainly Amethyst's features, aside from the extra eyes, the visor and the body suit, which is inherited from Garnet.
 * Sugilite is the only known Crystal Gem with three gemstones.