|Full Name: Shuichi Yoshihama|
|Impactor Designation: Logia|
Impactor Logia is the lead commander of the Impactors entrusted with the mission to destroy Earth at all costs, following his kind's code of honor. He assumed the guise of Shuichi Yoshihama, he posed as Wakui's assistant to get the Guntroller to use Guntras in his Solar Annilation, using the giant robot's oxygen supply to make the sun go supernova and kill everyone. But Lucia was wounded, Logia saved her as he has feelings for her as well. The guntroller end up with the Gransazer, the mission ends an absolute failure and ordered to fall back by his superior. However, Logia to summon DaiLogian to Earth and use it to destroy the Gransazers, taking out Tawlon, Remls, before going after Gorbion in a plan to upset Tarious. But the Pisces and Gans' interference saved their leader as he decides to wait for DaiLogia before calling our the Flame Tribe for a match between Garuda and DaiLogia before the others arrive to form DaiSazer. But when defeated by Tarious, Logia turns himself into a suicide bomber to taking the Sazer with him as they leave Earth's orbit. However, Logia drops Tenma at the last second once realizing this action would go against his pride as an Impactor.
However, he survived his suicide and resurfaces upon regaining Dailogian and his Hiro-Sniper from the JDSF's Scientific Research Lab, beginning his vendetta against the Gransazers by kidnapping Ryouko and Ran and capturing Tappei, leaving them at the mercy of a time-bomb while he goes after Tarious to personally kill him. But when the plan goes array, Logia summons DaiLogian to crush Tarious as the Yuuhi arrives to hold him, the GranVehicles arrive and drive him off. Logia later resumes his attack at the JD Weapon Institute to get Okito and Yuuhi under his control to hold Daisazer while weakened. But the plan fails and Logia goes to hell again after Dailogian is damaged by Daisazer, found by Belzeus who offers him another chance by increasing his power and reviving Logia in return for the Crystal Slab by taking Mika and Professor Horiguchi as hostages to force Tenma to hand deliver it to him alone.
Once he smashes the Crystal Slab, unaware that it's a fake, Logia fight Tenma to his heart's content until the other Gransazers arrive to free Mika as the Professor Horiguchi as they even the odds and force Logia to use DaiLogian to fight Daisazer until Belzeus is tired of Logia's arrogance, forcing him out of DaiLogian as it leaves under Belzeus control. Refusing to give up, Logia abducts Mika who tends to his wounds before he lets her go as he goes to hunt down the Belzeus-controlled DaiLogian and reclaim it as he and Tarious settle things in a one-on-one fist fight. But the fight ends in a draw as a satisfied Logia leaves, later returning to aid them in fighting Belzeus, though he still sees Tenma as an eternal rival. At the end, and bids farewell to Tenma. After that Logia realize that he was betrayed by Belzeus, he supported the other Gransazers in their final battle before arresting Belzeus.