Even as rivalries for land abound the world over, the Ultimate Emperor has requested information about his past be proselytised to the masses. Recoil before his achievements!
Beyond his glorious job of unifying Mobius and spreading imperial rule to various corners of the Mobian home galaxy, the Imperator is most notable for having singlehandedly struck down the Three Terrors, three demigod-like individuals that threatened Mobians and all sentient life - and all at the same time, no less!
The first of the Terrors was Knuckles the Echidna. Having donned the name "Enerjak," after a legendary - and near-omnipotent - evil, he went insane with power, believing it was his destiny to unite the world and lord over it to protect it. He engaged in such barbarous behavior as extracting life force from those who opposed him so as to fuel his Prelate Horde.
Unfortunately for this red-furred upstart, the Imperator was willing to defend his realm against evil. The two engaged in battle, Shadow's skill matched against Enerjak's raw power. Discovering this would get nowhere, the Imperator warped himself to where his intel had last reported the demonic Venice was located. By manipulating Venice - who was foolishly convinced he was the strongest creature in existence - into redirecting Enerjak's attacks back at him, the once-invincible demigod was easily crushed.
It was discovered Enerjak could not be killed, merely put in suspended animation. Somewhere in the universe, he is surely kept entombed, to ensure he never returns to threaten the world again.
This creature was beyond any semblance of noble goals or compassion. Everything that breathed was but a target. Apparently, he was born when a tortured youth came into contact with a chaos emerald - all his repressed memories and dark emotions became Venice, thoughts turned real by the volatile energy. Accordingly, all he knows is darkness, as it is all he is.
Death was secondary to pain, Venice seeming to feed off torment and misery. Killings were solely a means to extract grief. To demonstrate his capabilities, Venice once unleashed a series of disasters on a particular region, killing hundreds of thousands. This ranged from creating anxiety in the air to virtual fireballs - clusters of psychic energy that would rain down from great heights.
Fortunately for Mobius, the Imperator was there to save the rest of the world from such a fate. He had long determined chaos-energy based attacks would not work, nor would physical - Venice would simply psionically grab any who charged him and send them flying. The demon would naturally gloat at how he was invincible and how the world was his playground...
...but that last word got the Imperator thinking. Venice was a beast born from negative emotions. If nothing physical could defeat Venice, perhaps... he had an idea. He withdrew from combat swiftly, asking Venice to wait twenty-four hours and then go to the imperial stadium in Portal.
It was only natural the arrogant Venice accepted this challenge, proclaiming there'd be no more acts of destruction on his behalf during that span - he wanted the world to savor its joy so he could tear those hopes to shreds later on.
When Venice casually walked through the city streets, everyone naturally was silent and full of fear, making the monster grin. Mothers clutching their children, merchants cowering in their stalls as he proudly made his way through Shadow's great - and soon to not be so great - city.
Arriving at the stadium, Shadow promised Venice he'd be defeated this day. Venice found the thought hilarious, and decided to start with a warmup, only using light attacks.
This would prove fatal. Every speaker in the stadium began to play ... laughter. Children's laughter. All at once, at full volume. The sound permeated the air. Venice at first was confused, but found himself slowly driven more crazy - if that was possible - by the moment. The once-mighty demigod's moves became slower and sloppier, until eventually he was curled up in the ball on the floor, tremoring. Invincible to fists, artillery, energy blasts and the like, he was brought down by simple laughter. Happiness and joy were the antithesis to his existence, and so he was at their mercy.
Venice was later locked in an isolation chamber according to many reports, sounds of laughter always playing at full volume, with many backups. He has not menaced the world since.
Iblis was the third and final of the Terrors. As a contrast to Enerjak's well-intentioned extremism and Venice's sadism, Iblis was a force of pure destruction, more ammoral than immoral. Even if he did derive a disturbing enjoyment from watching things blow up.
No one knows quite where the Iblis came from. He appeared mere days after Enerjak and Venice were both defeated.
Iblis' first act was to kill Mobius' (second) greatest hero, Sonic the Hedgehog, also a key leader in the Resistance movement. With Sonic disposed of, Mobians swiftly rallied behind the Imperator to deliver them from evil.
Venice had shown some restraint, as had Enerjak. Not so with Iblis, who was entirely focused on leaving the universe a great, burning void, and then getting rid of that as well. Shortly after his appearance, he carved a path of destruction that killed millions. Mobius feared the worst, and only the Imperator, having donned his trademark, chaos-enhanced armor, was ready to stand against them.
Iblis had not tapped the Master Emerald, yet his power was even greater than Enerjak's - pure, undiluted chaos energy, with the ability to do whatever his narrow mind could think of. Fortunately, all he could really think of were "smash!" and "burn!"
Whereas it required tact to beat the first two Terrors, Iblis was easily conquered once one put it all together - the Master Emerald, which he lacked, could defeat him, but only if a person knew how to use its power. Only Guardians knew how to unlock its bizarre properties and utilise them, which put the Imperator in a situation. With the help of the mysterious "Angel," he was able to get this jewel to work. Iblis was sapped of his immense power and placed in chaos suspension.
The Imperator saw Angel as what he was - another enemy of the peace, but was unable to catch the sneaky being before he ran off.
Regardless, the Imperator had banished the three Terrors, and to this day many still revere him as a living god, a deliverer, a benevolent overlord.
What's wrong with you, people? can't you just go completing RL countries' borders? 
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