* First appearance: Battle 180
* Age: Early-30s
* Type: Dou
* Type: Satsujin Ken
* Yami Symbol: Ice
* Martial Arts: Command Sambo

Alexander Gaidar is the Command Sambo Master of Yami's One Shadow Nine Fists and the Master of Boris Ivanov. He grew up in Russia and at some time entered the army and managed to become a colonel. Later, he entered Yami and became one of the Nine Fists. He has long wavy light colored hair down to his shoulders and has strangely colored dark eyes. He typically wears an artists outfit and his military uniform.

Alexander is shown to be capable of switching from a nonchalant demeanor to a raging man in a second, not unlike Ogata but with a lot less control. He took up sculpting and painting in order to create an atmosphere of peace to distance himself from the constant fighting. He particularly hates guns, which he refers to as "dirty metal", and if not in battle with somebody else, will kill a person who points a gun at him immediately regardless of the person's affiliation. He seems to have a lot of pride in Sambo and tried to prove that modern Sambo was far superior to the ancient traditional Jujutsu that Akisame uses. He seems to care for Boris's well being, as seen when they have a lot of conversations and disowned Boris as his disciple in order to prevent the latter from being possibly killed by Yomi.

Strangely enough, he was very certain on instructing Boris that he should always stay cool on the battlefield, because "people who lose their cool on the battlefield, die" as he says, despite being a man that loses his temper extremely easy and proceeds to destroy everything around in very frequent fits of rage. This could be due to his knowledge of the difference of their fighting styles, with Boris being a Sei-type fighter and he being a Dou-type fighter.