Land Pollution Vice-Minister Hiramechimedes

"Pok-Pok-Ping! And a flash comes to me. Land Pollution Vice-Minister Hiramekimedes!" (ポク・ポク・ピーン！とひらめくは、害地副大臣ヒラメキメデスです, Poku-Poku-Pīn! to hirameku wa, Gaichi Fuku Daijin Hiramekimedesu desu)

Land Pollution Vice-Minister Hiramechimedes (害地副大臣ヒラメキメデス, Gaichi Fuku Daijin Hiramekimedesu, 15-24) is Yogostein's subordinate and Gaiark's top tactical genius, a more serious threat than the Pollution Ministers. Whenever inspired with a plan, the 3 lights on his head flash as he says "Pok-Pok-Ping!" (ポク・ポク・ピーン!, Poku-Poku-Pīn!) with the sextant, and protractor on his chest body indicating the plan's greatness. In spite of being low ranked, Hiramechimedes is feared by the Engines, making them frightened husks of their former selves in his numerous victories which they enventually overcame. However, on the day Gaiark was expelled from Machine World, Hiramechimedes mysteriously disappeared during the fight only to resurface months later on the Human World to serve under Yogostein again after settling some loose ends with the Wing Engines as he thought he had handled, only to be once more pursed by them and the Go-on Wings.

Eventually, Hiramechimedes, along with Yogostein and Bōseki Banki, stages his appearent banishment from Hellgaille palace as part of a plan to deceive the Go-ongers and kill Go-on Gold. However the plan goes wrong yet again with the arrival of Engine-Oh G9 and Hiramechimedes refuses to return to Yogostein out of shame, spending long days of calculation for a means to kill the Go-ongers. After a vain attempt to destroy the Go-on teams, Hiramechimedes finally finds the answer he had been looking for: to beat the Go-ongers at their own game with raw power rather than with intellect. To that end he sneaks back into Hellgaille Palace and, inspite of Yogostein's pleas, infuses himself with a hundred times the Bikkurium amount that a Savage Machine Beast needs for "Industrial Revolution". In consequence, the stress of this destroyed Hiramechimedes' mind as he upgrades into a more powerful and insane babbling form called Detaramedes (デタラメデス, Detaramedesu). Though he almost defeats Engine-Oh G9 after executing "Big Industrial Revolution", Detaramedes's downfall comes from Sōsuke's reckless refusal to give up. In the end, Go-on Red scraps Detaramedes with only the Hacalibur remaining for Yogostein to collect.

However, while the Go-ongers visit a shrine in the woods, they encounter Hiramechimedes' ghost, refering to himself as Urameshimedes (ウラメシメデス, Urameshimedesu) and has teamed up with a being called Bakki (伐鬼（ばっき）, Bakki) from Samurai World. Even after scaring the Go-ongers, Hiramechimedes is finally put to rest by another G9 Grand Prix.

His attacks have a calculus theme from his Pi Beam (円周率パイビーム, Enshūritsu Pai Bīmu) to his sword-based Equilateral Triangle Slash (正三角形斬り, Seisankakkei Giri), Isosceles Right Triangle Slash (直角二等辺三角形斬り, Chokkaku Nitōhen Sankakkei Giri), Acute Triangle Slash (鋭角三角形斬り, Eikaku Sankakkei Giri), and Hiramechi Kill-Factor: Pythagorean Theorem (ヒラメキ殺法・三平方の定理, Hirameki Sappō: Sanheihō no Teiri) attacks. As Detaramedes, his uses a variety of attacks with a miscalculation theme such as Hissatsu: Root 3 - Base ÷ Diameter = 950000 (必殺・ルート３－底辺÷直径＝９５００００, Hissatsu: Rūto San Hiku Teihen Waru Chokkei wa Kyūjūgoman), 10 - 4 = 200 (１０－４＝２００, Jū Hiku Yon wa Nihyaku), 6 + 9 = 500 (６＋９＝５００, Roku Tasu Kyū wa Gohyaku), Detarame Kill-Factor: Bikkurium Beam (デタラメ殺法・ビックリウム光線, Detarame Sappō: Bikkuriumu Kōsen), Detarame Kill-Factor: Brain Freeze Slash (デタラメ殺法・思考停止斬り, Detarame Sappō: Shikō Teishi Giri), and Detarame Kick-Punch-Chop-Slash (デタラメキックパンチチョップ斬り, Detarame Kikku Panchi Choppu Giri). His names are from the Japanese words for "flash" and "brillance" (閃き, hirameki), "nonsense" (出鱈目, detarame), "grudge" (恨めしい, urameshii), and "Archimedes" (アルキメデス, Arukimedesu). Before entering battle, Hiramechimedes says, "Pok-Pok-Ping! And a flash comes to me. Land Pollution Vice-Minister Hiramechimedes!" (ポク・ポク・ピーン！とひらめくは、害地副大臣ヒラメキメデスです, Poku-Poku-Pīn! to hirameku wa, Gaichi Fuku Daijin Hiramekimedesu desu).

Kokorootomedes
Kokorootomedes (ココロオトメデス, Kokorootomedesu) is Hiramechimedes's older brother who is a transgender and appeared in Special DVD. He wields the sword Karadecolibur (キラデコリバー, Kiradekoribā). When he upgrades into a powerful form, he turns to character like Yakuza. He is scrapped by Go-on Red. His attacks are Kokorootomedes's Fashion Check Attack (ココロオトメデスのファッションチェック攻撃, Kokorootomedesu no Fasshon Chekku Kōgeki), Love Sparkling Pentagon Star Heart Slash (恋のキラキラ五角形お星様ハート斬り, Koi no Kirakira Gokakkei Ohoshi-sama Hāto Giri), and Hissatsu: Battle without Ruler (必殺・定規なき戦い, Hissatsu: Jōgi Naki Tatakai). His name is from on the Japanese word for "heart" (心, kokoro), "maiden" (乙女, otome), and "Archimedes".