Long

Long (ロン Ron?) is the coordinator of the Gen Jūken, its actual leader. Though he refers to himself as a master of the Gen Jū Dragon-Ken (幻獣ドラゴン拳 Gen Jū Doragonken?), Long is not a human but an immortal known as the Infinite Dragon (無間龍 Mugen Ryū?, 48-49), a massive many-headed golden dragon with terrible power who manipulated the fate of humanity behind the scenes out of whim. Because of his immortality and evil nature, he found the world to be "dull" and decided to make it "interesting" for himself by creating the Destroyer. To that end, Long devised a means to bring Maku to his side, secretly aiding in the foundation of the Rin Jūken Akugata while conditioning Maku to become the Destroyer. But after the Kensei sealed Maku and the Kenma, Long was forced to wait until another ideal pawn surfaces to take Maku's place. Assuming the guise of a human, Long murdered Rio's family, leaving only a young Rio alive to undergo the needed conditioning. Long also mortally wounded Dan years later before decimated the village where Jan was born to insure no interference from any of Dan's kin (Jan's survival of Long's assault was by accident). Setting up the Gen Jūken, he used the Blood-Oath Ceremony (血盟の儀式 Ketsumei no Gishiki?) to convert others into the Gen Jūken, turning some into his servants.

Long originally hid behind the scenes while overseeing Rio's training, with only Mele knowing about his presence in Rin Jū Hall. He even comforted her to an extent by revealing to her that Rio will obtain Fury Confrontation Ki and defeat Maku, setting up the events for it. Furthermore, Long evoked Gou's transformations into the werewolf until Bae's interference stopped that. Long was further vexed to learn that Rio is making his way to the Beast Origin Village, managing to have Rio turn back in the guises of Jan, Gou, and Xia Fu, revealing the existence of the SoZyuTo that Rio needs to enter the village freely. Long also uses the same illusory power to force Mele to take the SoZyuTo from Ken while he's defenseless. Once Rio and Mele make the run for the Beast Origin Village, Long revealed himself at last to Maku, using himself as a distraction to allow Rio safe passage to the village.

When the Kenma had served their purpose, Long arrives to kill Rageku in his fighting form, with the Kenma realizing who he is. With the deed done, Long fully reveals himself, offering Rio a chance to master the Gen Jūken to become even stronger, converting both him and Mele in the Blood-Oath Ceremony to further his scheme. However, seeing Jan as a hindrance his plans, Long attempts to kill him behind Rio's back. But ironically, Jan managed to awaken Rio as the Gen Jū King; much to Long's praise. Mele's interference ruined it, with Long's treachery and true identity revealed as a result, before beating Rio to find out why he didn't completely become the Destroyer. When Mele interferes once again, Long attempts to kill her, only to have Rio jump in front of her to shield her from the blast. Seeing Mele as the cause, Long takes her as a hostage so Rio can resume his part in the master plan. But once his plan is completely shattered, Long decides to kill them all and start finding a new Destroyer to replace Rio, however, Long is soon seemingly killed by SaiDaiGekiRinTohja. However, his spirit endured and entered Sanyo, using him to recreate himself. Now with a newfound interest in the Jūken power that rivals his own, Long assumes his true form to personally destroy the world himself. Mele sacrifices her self to save the Gekirangers from one of his attacks, after which Gou and Ken try and fight with GekiTojahWolf and SaiDaiOh, but Long effortless defeats them both. Rio attempts a suicidal to kill him but Long survived because of his immortality, though he was forced back into his human form and laughed at that Rio thought he could kill him. Long then assumes his fighting form and overwhelms the Gekirangers before leaving to rampage through the city. Gou and Ken later to fight him, along with Kensei but they were no match for him. Long finally met his match when Jan, Retsu, and Ran returned after mastering the Rin Jūs-Ken. However, because Long was immortal the Gekirangers couldn't kill him, so they instead sealed him in a small ball for all time, with Jan safeguarding the small golden orb that Long has become.

During the events of Engine Sentai Go-onger vs. Gekiranger, Meka uses the Engine Souls as hostages to force Jan to give him the sealed Long, converting his sealed body into the Dōkokugan Soul (慟哭丸ソウル Dōkokugan Sōru?) before installing it into Nunchaku Banki to empower him as part of his plan to use the dragon's power to rule the world. But when Nunchaku Banki shuts down, the seal partially break as Long manages to emerge, bent on extacting his revenge on the Gekirangers to regain his freedom upon their deaths until the revived Rio and Mele arrive. Converting the Savage Machine Beast into a new form to inhabit, Long Banki (ロンバンキ Ron Banki?), Long battles the two Sentai groups until his vessel is destroyed by the Engine Beast Grand Prix, forcing him back into his sealed form.

His name is based on lóng (龙), the Mandarin word for "dragon", and motifs are the Azure Dragon and the Dragon of the Earthly Branches (though ironically, his fighting form is gold colored), both of which were said to be based on his true form along with every culture's experience with a dragon as Xia Fu speculated.

Long is portrayed by Naoki Kawano (川野 直輝 Kawano Naoki?).