Mercury was a master of Chudo Karate.
More than a hundred space karatekas attempted to join the Space Karate Forces as reserve members before the Block-B semifinals of the Tenth Zenith of Things Tournament in ES 591. During the free for all that Zekka had them undertake as a means of trying out, Mercury questioned Rakan if he mocked the "sacred battle among men" that they were engaged in, as the former had complained about the lack of women. Three other karatekas, Zakuro, Amin, and Ganga, recognized Rakan as a wanted criminal. Collectively agreeing to take him out for the honour of the karate world, all four attacked simultaneously, but all except Mercury fell to Rakan's Finger Thrust without even touching him. Mercury managed to end up back to back with Rakan, but had been slashed in the head and began to feel the effects of the polonium that Rakan had tipped his fingers with, which started to violate his brain cells. Mercury tried to spin around and hit Rakan with a horizontal chop, but the latter dodged and drove his left hand fingers first into Mercury's face. Rakan then mocked the mercy of the samurai over Mercury's body.