Obsidian is the fusion of Ruby, Sapphire, Amethyst, Pearl, and Steven or Rose Quartz. She makes her debut in the final battle against the fully formed Diamond Mech, where she directly fought and defeated it. Previously, when the fusion was formed with Rose, she helped Wiliam Dewey after he was stranded at sea, allowing him to discover and found Beach City. She is a fusion used primarily for power, relentlessly attacking opponents and lacking any dialogue other than angered screaming.

Tier: At least High 6-A, likely higher |At least High 6-A, likely higher

Classification: Gem (Rose Fusion), Gem/Human Hybrid (Steven Fusion), Crystal Gem, Fusion of Rose Quartz/Steven Universe, Ruby, Sapphire, Amethyst, and Pearl

Powers and Abilities: Superhuman physical characteristics, gem physiology, regeneration (High-Mid), immorality (Types 1 and 3), shapeshifting, size manipulation, body control, biological manipulation, fusionism, self-sustenance (Types 1,2, and 3), automatic-adjustment to different strengths of gravity, pocket reality manipulation, sealing (Via Bubbles), and BFR, additional arms, large size (Type 2), weapon creation, magma manipulation, fire manipulation, heat manipulation, breath attack, can create shockwaves, and gusts of air just by moving and screaming, surface scaling

Attack Potency: At least Multi-Continent level, likely higher (Should be considerably stronger than Alexandrite. Cleaved through the blue and Yellow Diamond Arm ships and could cut into the white diamond Torso ship, the former two being able to contend with a partially-formed cluster)|At least Multi-Continent level, likely higher (Should be considerably stronger than her part human counterpart)

Speed: At least Relativistic, likely higher combat speed, reactions, and short burst speed

Lifting Strength: At least Class G (Should be stronger than Alexandrite)

Striking Strength: At least Multi-Continent level, likely higher (Cleaved apart several of the diamond ships and could throw around the Diamond Mech with their physical strength alone)|At least Multi-Continent level, likely higher (Should be considerably stronger than her part human counterpart)

Durability: At least Multi-Continent level, likely higher (Could withstand being slammed into a wall by White Diamond's Torso/Head ship, although this unfused her with a second attack. Capable of taking direct hits from Yellow and Blue's arm ships. Capable of forming Steven's shield)|At least Multi-Continent level, likely higher (Should be considerably stronger than her part human counterpart)

Stamina: Limitless so long as her gems aren't damaged or destroyed

Range: Over a hundred meters through sheer size, higher with her sword

Standard Equipment: Can create Garnet's Gauntlets, Pearl's Spear, Amethyst's Whip, Stevenson Shield, and form a sword out of each weapon

Intelligence: Presumably high due to being comprised of Pearl, Amethyst, and Garnet along with Steven or Rose, although large enough fusions tend to have trouble coordinating thoughts and speech. Skilled in combat, however.

Weakness: Sufficient damage to her physical form can revert her back to her vulnerable gem form, which can be broken and destroyed. Sufficient conflict between gems can destabilize the fusion. Fusions that are comprised of a large number of gems are much more unstable by nature and have trouble forming coherent thoughts and ideals, although this can be somewhat negated by having a clear, common goal.

Notable Attacks and Techniques:

•Weapon Proficiency/Fusion: As a fusion of multiple gems, Obsidian is skilled in wielding a variety of weapons, such as Pearl's Spear, Garnet's Gauntlets, Amethyst's Whip, and Steven's/Rose's Shield. She can additionally fuse these weapons to form the hilt of a sword, whose blade can be constructed by the magma in her mouth.

•Magma and Fire Manipulation: Obsidian has a pool of magma in her upper mouth, which she can use to form a white-hot sword. She additionally gives off fire and ashes around her body and eyes.