Spartan is a saint with great telekinetic powers, exclusively created for the anime adaptation of Kurumada's manga.
In anime-only events, Spartan accompanied Perseus Algol and Ophiuchus Shaina on their way to kill the Bronze Saints. He uses his telekinetic powers to bring down the plane where Seiya, Shiryu, Shun and Hyoga were on their way to the Sanctuary, and faces Shiryu, controlling all his movements and making him hit himself.
However, he is accidentaly turned to stone by Perseus Algol's Medusa Shield. After Algol died, he was reverted to normal, but fled with Shaina (at great speed) after her defeat. He was never seen again.
Spartan's constellation or rank is never mentioned in the series, although he is presumed to be a Silver Saint. He wears a generic Cloth.