Brimstone is a member of the Star Seekers crew.
Brimstone was a crewman on the pirate ship Tidal Wave, commanded by Thundertron. He and Cannonball killed Arclight when the Junkion protested the enslavement of his kind by the Star Seekers.
Some time after the battle on Junkion, Brimstone, along with the other Star Seekers, engineered a ruse to trap the Decepticons and to wipe out the Nemesis with the Requiem Blaster. Taking advantage of the Blaster's high energy consumption rate, Megatron manages to best Thundertron in hand-to-hand combat while the Nemesis overwhelms the Tidal Wave, forcing the pirates into a retreat.