Halimede was a tertiary class pallasite. He is not a human. As a pallasite, his time control and another powers, depends of his weapon (Sansetsukon) and with out it, the distortions made by him disappears.
Halimede was sent to attack Rosan to kill Ryuho in the begin of the battle against Pallas; Ryuho's Draco Cloth don't arouse, so, Ryuho can't fight fairly against Halimede, that tries attacking Chun-Li (Ryuho's mother). Ryuho's blood touches the cloth, stone of the Draco Cloth, and it turns a Pandora Box Cloth, and now, Ryuho using his clout has defeated Halimede.
Like Tarvos, Halimede leads an attack on a little village. Ray and his brother, Phillip, escape from the city, but gets trapped in a abysmal. Shun arrives tosave them, but he doesn't kill Halimede, because hates to injure enemies, and Halimede promises don't doanything wrong, if Shun don't kill him. Shun accepts, and Halimede uses his Chrono Delayed to stop the time of Phillip and Ray, but Phillip uses his body as a shield and protects Ray, so, only he was frozen.
Halimede uses Ray and his hatred on Shun, to inducehim to steal the Andromeda Cloth, Stone, in exchange to turn Phillip back to the life. Ray steals Shun's cloth, stone, and Halimede gets surprised with such a great achievement. Halimede doesn't allow Shun take his cloth, but Shun accepts to die, because Halldeme promises give the life of Phillip if Shun dead.
But Ray tries attack Halimede, and in this attack, take the cloth stone of Shun and gives back to him uses against Halimede. Halimede after was defeated, get away and leaves Phillip frozen.
Halimede tries stop Laki and her mission to give stardust to his sensei (Kiki) cures the cloths injures. But, Subaru and Kouga appears to fight against him. The Subaru cloth wants not to fight, and Laki (still in that place) tell to he that his cloth is crying. After Subaru accepts the cursed destination of the Equuleus Cloth, and promises don't die, the clothe accepts him, and he destroys Halideme.