Stativarius

The Stativarius (ステートバリウス) is a special type of violin, said to produce the greatest music in the world.

Etymology
"Stativarius" is a pun on the real-life (ストラディバリウス), the legendary string instruments built by the Italian luthier family Stradivari during the 17th and 18th centuries, known worldwide.

The names of the known individual Stativari are derived from figures from folklore and mythology, most of them involving.

Principles
The Stativari are very valuable and can sell for more than a hundred million yen at auction. Due to their reputation as violins which produce the world's greatest music, Blue Blood gave Stativari the additional value of being 'keys' for their exclusive services.

However, the Stativari also have an additional hidden value, as they are actually autonomous parasitic spiritual items produced during the Rosicrucian age. Through the amplitude of their notes, the Stativari can invoke the elements in order to cast spells.

Background
The Stativari were constructed at least 300 years before the present, as products of the Rosicrucian age.

At some point after joining Shokuhou Misaki's clique and being introduced by her to the Chandelier Auction House, Sakibasu Yuri managed to obtain the Stativarius Ainsel. At another point in time, her mother Sakibasu Ryouu obtained Stativarius Tam Lin.

Toaru Kagaku no Railgun SS3
While captivated by the Stativarius Ainsel, Sakibasu Yuri challenged Shirai Kuroko in a violin contest. With help from Misaka Mikoto, Uiharu Kazari and Saten Ruiko, Kuroko managed to win against the Stativarius, resulting in Blue Blood targeting them in order to eliminate evidence of the incident, out of fear that it would shake confidence in their 'keys' and threaten the network they had built up. During the events which followed, Mikoto's group realized the additional value which had been attached to the violin and used this clue to guide their investigation.

When Sakibasu Ryouu attempted to infect Zero-Day Link, she used Stativarius Tam Lin's offensive capabilities against Mikoto, Kuroko, Shokuhou Misaki and Hokaze Junko. She was defeated when Yuri arrived and used her Ainsel in the same way, supported by her friends' efforts, to overcome her use of Tam Lin, but the intelligence lurking within Tam Lin emerged and convinced her to surrender her body to its control. Despite gaining the upper hand through its spells, Tam Lin was defeated when Yuri managed to use Ainsel in a similar manner (with her ability mitigating the effects of the rejection reaction from using magic while being an esper) and push it back, creating an opportunity for Mikoto to destroy the violin.

Trivia

 * Similar to how Stativarius is derived from the real-life Stradivarius, two other types of violin are referred to which are derived from real-life Italian luthier families and the violins they produced, of similar standing to the Stradivari; Almati from and Guarnari from.