Helex is the Decepticon capital and the seat of Megatron's empire, though he doesn't seem to spend much time there. As their capital, it may be assumed to be situated well into Decepticon territory, possibly not far from Stanix. The Power Base serves as their main headquarters.

Fiction

Generation 1 continuity family

Marvel The Transformers comics

While Polyhex had been the preferred location of many previous Decepticon leaders, Helex became the hub of the reign of the Triumverate. Rather than invest in the war, the Triumverate opted to use their power solely for their own comfort. Their decadent pursuit led to the abolishment of the many patrols keeping the city's metal vistas clean from Autobot presence, which began to manifest itself without challenge in the city soon after. As the Autobots plotted to tip the power balance in their favour, the Triumverate unworriedly entertained their forces with a steady program of arena fights in which they pitted their more bloodthirsty soldiers against Autobot prisoners of war.

When "Megatron" and Ravage returned to Cybertron following the events of the Time Wars, they were furious to find Autobots walking around Helex without fear, so naturally they murdered them all. The two stormed off to the capitol to confront the ones responsible for this mess, and after what they had seen outside, they were not surprised when they came to meet the lazy, high-grade oil drinking Triumverate. Knowing that their forces missed the days of conquest and would be easily convinced to replace them for Megatron, the Triumverate manipulated their rival into arena combat to reclaim his title the traditional way. They didn't fight him personally, but sent some of their warriors to kill him. Megatron fought well until he regained his composure and delivered a rousing speech that convinced the Decepticons to his side. The Triumverate tried one last time to take him out, but the Triggercons shot them before they could, signing the return of the reign of Megatron. The Fall and Rise of the Decepticon Empire.

"Megatron" continued to rule out of Helex, though tormented once more by Straxus's programming left in his mind. Coincidentally, the real Megatron showed up from the Dead End at this time and battled his way into the capitol Mind Games to kill his clone before Straxus would take over. "Megatron" realized Megatron's story about him being a clone was true and chose to kill himself rather than allow Straxus to return, handing his real self-control of the empire. Two Megatrons!

Unlike his fake self, Megatron didn't linger in Helex, but set up camp somewhere else.

2005 IDW continuity

Momus came from Helex, Remembrance Day as did Swerve. More than Meets the Eye #42 solicit Helex was taken by the Decepticons during the Fall of the First Five Cities early in the war. Life After the Big Bang

Beast Wars: Uprising

The Resistance conquered Helex during the Grand Uprising. Safe Spaces

War for Cybertron Trilogy marketing material

Helex was one of the first cities to fall during the Decepticon revolution and became a stronghold as the war for Cybertron commenced. Siege Teletraan-1 Data Files

Shattered Glass

When Starscream's crew managed to make contact with Cybertron, Heatwave told them that Megatron hadn't taken their call because he was away in Helex. Transhuman

Notes

• Castle Decepticon, which is described as Megatron's home, might be located in Helex.
• Helex was created as the Decepticon answer to the Autobot capital of Iacon, but hasn't been able to keep that title in later canon. Within the same continuity and by the same writer, albeit in the unofficial story "Alignment", Helex was replaced as the Decepticon capital by Kolkular. Kolkular was canonized in the Dreamwave Generation One continuity a few years later and reimagined as the capitol of the Decepticon city-state Kaon. Kaon has since become Iacon's counterpart in virtually any continuity while Helex is little more than a footnote.