Klein (クライン, Kurain) is one of the 10,000 players who were trapped in Sword Art Online and the guild leader of Fuurinkazan (風林火山, Fūrinkazan), one of the clearer guilds. He became Kirito's friend after he asked Kirito to show him how to play Sword Art Online. He later began playing ALfheim Online as a Salamander. His real name is Tsuboi Ryoutarou (壷井遼太郎, Tsuboi Ryōtarō).
Powers and Stats
Tier: High 8-C
Name: Tsuboi Ryoutarou
Origin: Sword Art Online
Age: 22 (Beginning of Aincrad arc), 24 (End of Aincrad arc, Fairy Dance arc), 25 (Phantom Bullet arc)
Attack Potency: Large Building level (Should be stronger than the characters that defeated the GeoCrawler, a beast with the height of a house and the length of multiple houses)
Speed: Supersonic+, with Hypersonic+ reactions (Was able to keep pace with monsters above the 75th floor.)
Lifting Strength: Peak Human
Striking Strength: Large Building Class
Durability: Large Building level
Range: Extended melee range
Standard Equipment: His katana, the Karakurenai
Intelligence: Average, was able to lead a guild
Weaknesses: His flight only lasts for ten minutes
- Reaver: Is a charge-type Sword Skill that delivers a single, fast thrust with a forward jump. The skill is activated by lowering one's stance and raising a one-handed curved sword atop one's shoulder.