Rumbling Thunder

Thunder sports a big, spiked head of hair framed by long sideburns. His coat is trimmed with fuzz at the collar and cuffs and carries a lightning bolt stitched over the belly, and he rounds out the look with trousers cut to the knee.

Not much of Thunder's character is on display, though he carries the same self-assurance as the rest of the Heavenly Ninja Party, fitting for a Ninja Village graduate. He nurses a bitter grudge against Flashy Flash for razing the village, a resentment that hints at lingering loyalty to the place despite its brutal training. Alongside that, he shows genuine solidarity with his fellow ninjas, standing shoulder to shoulder with them.

Thunder came out of the Ninja Village's 37th graduating class, nicknamed Golden, the same cohort as Gale Wind and Hellfire Flame, before joining the Heavenly Ninja Party. That group cornered Speed-o'-Sound Sonic at his hideout to spell out its aims, a scheme for world domination and the deaths of Flash and Blast, all directed by Empty Void, whom they call That Man, and ordered Sonic to bait Flash into a trap. When Sonic instead dueled Flash outright, the party broke in and took on both of them, branding Sonic a traitor. Blast then arrived, beat the ninjas down, and teleported everyone to Sonic's hideout, where Saitama had already toppled the Ninja Village's leader. Thunder and the others threw themselves at Saitama and were flattened one after another, then watched Blast and Void destroy the divine beasts Byakko and Genbu. Awed by Saitama's power, the group tried to make him their master, and after he refused they resolved to trail him. His skills are reckoned to match Gale Wind and Hellfire Flame in their base forms, backed by strength, speed, and reflexes far beyond an ordinary person's, keen stealth, and a thunderbolt-shaped sword, doubled to twin blades in the webcomic.