From Sonic Retro
Commander Brutus was a character in the Fleetway's Sonic the Comic. Seeking to create for himself a right-hand man, Doctor Robotnik selected Brutus, formerly a Badnik troopers in the Special Badnik Service (SBS), to be programmed with a copy of his brainwaves, in order to create the ultimate trooper.
It's unclear what reconstructions and modifications his armour and appearance may have undergone before being programming as such, but when programmed, his armour was stated to be constructed of the near-invincible Mobian metal, megatal, and was a golden colour (in contrast to the typical red trooper colour). For flair, he wore a cape. Brutus was also outfitted with an anti-gravity unit, but it is specifically noted that he possessed this before being programmed with Robotnik's brainwaves.
Operating as Robotnik's second-in-command, it wasn't long before Brutus confronted Sonic in the Pleasant Zone, and proved to be more than the hedgehog and his allies could handle. As things looked like they were all over, Sonic transformed into Super Sonic, and now had the power necessary to shatter Brutus' armour, proving so by demolishing his arm. Brutus was forced to order a retreat, and then suffered a reprimand from Doctor Robotnik, as he had embarked on the mission with his permission. But what Robotnik did not realise was that in programming Brutus with his brain patterns, he had transferred all of his thoughts and desires to Brutus - and now, Brutus too sought to rule Mobius!
With his shattered arm replaced with an energy weapon, Brutus set about capturing Mobians to be converted into badniks - for his OWN private army. His first attempts met with interference from Johnny Lightfoot but he eventually mustered a full fighting force, and soon attacking the Metropolis Zone, home base of Robotnik's operations while a secondary force attacked the Casino Night Zone.
The conflict was brutal, leaving the Metropolis Zone half-wrecked and with Brutus swiftly beating Robotnik's forces, even breaking into Citadel Robotnik and revealing the self-destruct program Robotnik had implanted in him (same as with the Metallix's) had long ago been excised. Johnny and Amy Rose were briefly converted into Badniks, and both Sonic and Shortfuse the Cybernik proved no match for him. Eventually Brutus clashed with Robotnik himself, decked in an armoured combat suit. In the end, Robotnik claimed victory by dousing Brutus in liquid nitrogen and shattering his body, destroying him. Robotnik swiftly took control of Brutus' Badnik army and made a planetwise broadcast to Mobius proclaiming that this only confirmed that nobody could ever defeat him.
It is interesting to note that Brutus is one of the few foes that Sonic has never actually been able to defeat. In each battle with him, Sonic has been outmatched and had to resort to becoming Super Sonic to defeat him the first time.