One thing that I hope you notice in the Red World is that the villains are not all allied. In fact, there is not only one "axis of evil," but there are many who use similar tactics. They all mass-create demons. Some prefer subtlety, others strength... Toward the end of Red World history, the following shocking events occur:

Setting: Nastar has been overthrown by men. The Empire of Mankind has begun to prosper again, but was then threatened by a new evil. The Black Cross was re-pieced, and allying with other dark powers it surged into the northlands, stealing half of the kingdom in weeks. Men struck back, but headway was slow, until all at once the enemy army retreated back to the Shadow Realm.
(-)
The northern half of the Red World was freed nearly as fast as it had been overrun, but this gave little comfort to the armies of men. Strange tales has gone around the whole common world of a shadowy presence that left flames in its wake, and night by night fewer stars shown in the sky. The sudden flight of their demon enemies and their dark powers made them only more sure that some dubious force was at work, playing with them.

They figured the retreat was a feint, and advanced cautiously, but every mile they advanced the marks of a hasty retreat were evident as everything but weapons was discarded on the wayside. At last they found the lead they needed, a wounded demon struggling northward. Interrogating him they obtained the strangest of news: a rebellion had begun in the underworld, and all the armies were brought back to fight.

Only the wisest of them foresaw the doom that was upon them.

The hosts of the Black Cross rushed with all haste into the Shadow Realm, but found it already desolate. Villages and towns had been turned to rubble and fortresses leveled. The mines remained sound, and the mightiest cities were untouched, but over all the hills and plains a thick smog hovered.

Even as they marched northward the army was stopped by a great vision in the sky....

Nastar had returned. Unforseen, unlooked for, and unbidden his spirit had broken back into the world. It walked now without fleshly raiment, in purest blackness and in a hulking humanoid form. Only his eyes and his mouth remained distinguishable from the darkness that made his body, and these appeared as fires burning in the furnace of his soul. His very presence had cowed most of the Shadow Realm to follow him again, and his sheer might had overthrown the others. City walls were as child's blocks with the sweep of his arm, and the stoutest hearts melted at his gaze.

He quickly re-organized the underworld, bringing its labors to a fever pitch greater than that when he had last ruled. Swords he made in finer quality than any demon lord, and armor he produced just as fast. His would have been the greatest of all demon hordes ever to roam the earth, had not an unforseen tragedy struck him and all the rest of the world...

He quickly re-organized the underworld, bringing its labors to a fever pitch greater than that when he had last ruled. Swords he made in finer quality than any demon lord, and armor he produced just as fast. His would have been the greatest of all demon hordes ever to roam the earth, had not an unforseen tragedy struck him and all the rest of the world...

Nastar's reorganized underworld operation was nearly ready to strike back into the upper worlds when aforementioned tragedy struck. Even as he massed his armies in the capital, The Dark One returned. Aerykun broke out of Gor Xander Burld, fording across the fires into the Shadow Realm.

Nastar's lieutenants feared to tell him the terrible news. They knew that Aerykun could undo any power of demons, having been their lord once he was sure to be stronger. When at last they summoned courage enough to enter his chambers, they were empty. His armor was off the wall, his ball-and-chain (which the new Nastar preferred over the traditional sword), and even his dark presence had left. They knew immediately, despite all disbelief, what he had done. Their leader had went to face Aerykun, the Lord of all Demons, the Dark One, Fentre Jourin, alone.

The two met in the wastelands between the southernmost end of the Deep Island underworld and the great cities that lay toward the northern end. They stared each other down, each with nearly has terrible a form as the other.
Nastar's form was the more simple: evil dripping from his brows and his eyes and mouth burning brighter than ever. His strength had grown as his personality shrunk. He had become a nameless being of wanton destruction. His ball and chain hung at his side, the weakest of his weapons despite its hundred-pound weight.
Aerykun stood opposite him, grinning without moving his mouth. Aerykun stood a few inches taller, with his ancient ivory-colored armor obscuring his self, which was of no color at all, not even black. It could not be described by human eyes, only as the color of a void, which was different to all men, but equally horrifying. His sword, a dozen feet in length and as heavy as Nastar's mace, hung motionless at his left side, with which he could wield it as well as the right.
"So, Nastar, greatest of my creations, will you surrender to me all that I have empowered you to obtain, as we once agreed?"
"You know, Master of Old, that I will not."
"Indeed, Nastar, I have known that since I made you. For if indeed you had labored for me all these ages you would never have made this underworld so great, or the world above so weak by your attacks."
Nastar grinned in reply, he knew this as well as Aerykun.
"You built me, Aerykun, to make a kingdom, nay, an empire, worthy of your power. Worlds have fallen to me and men have knelt, but I will do nonesuch to you."
"Then you will die." But Aerykun did not raise his sword.
"You cannot kill me. For as my kingdoms have been ever as great as yours, so also I have become to strong for you to speak only the word and fell me. Indeed, by force of arms and by strength of your person all that I have built could be overrun, but precious little would you gain. This underworld would become like that above it, ravaged and unpopulated."
Aerykun's inner grin became a grimace. His prodigy spoke well.
"Then as you cannot kill me, for my strength, so also I cannot slay you and your's, for I have need of what strength you have amassed. This then, will be our resolution..."

*to be continued*

...This then, will be our resolution. As I am greater than you so you shall be lesser to me, but to me alone, for such you are. As I, once the weaker, fled this Deep Island now shall you go to whence I hid. Do as you have done here: build again another army, another empire, and ravage the worlds for what few years are left. Our places we shall exchange, that we may both live long and prosper, and that our enemies may die."
"This word is too simple, Master of Old. You speak to plainly, such is not your way. You seek to deceive ever, but have you forgot that such nature you put into me undiluted? Indeed, a price you must put on this bargain, or I know that I am cheated, for naught is given free that is worth anything by those of the earth."
The grin returned inside Aerykun, but still his face sat unchanged. "Nastar, you have been my right hand. As such, we shall seal the bargain with your left. Across the fires you shall go, and into them shall go your left hand. You shall stay on the other side, in my world whence I hid, there to build and to destroy men and dragons as you wish, but if ever you cross back here your hand which was put in the fires shall burn away. But if I call for you, and give you leave to join me, or if the fires burn out as the worlds unsunder, your hand shall be restored."
"To cheap a bargain, Aerykun. Still you seek to deceive me. Thus shall we know then that neither of us is the liar: not only my hand, but my left eye as well shall be placed as collateral on my word not to return against you. But then, how should I know that you will come not over to my world to undo me? Lay your right hand in the fire, for such was I you say."
"My right hand, though, is worth all your life. If it goes in the fire you must add more to your side of the scale, or it shall be weighted to me. By my power shall the pledges be set, by mine only can they be retrieved. Add then one more thing also: your hand, your eye, and your voice to speak. You shall speak no more, that I know you shall not deceive me."
"It is even, Aerykun. You shall be again my king, knowing that you protect me, and I shall be your liege, and you shall know that I can do naught against you."
Thus agreed, the two went to the edge of the underworld, climbing the mighty peak that soared into the sky there, which was ever the gate out of the Shadow Realm. There they struck off their hands, left for Nastar and right for Aerykun. Then Aerykun took Nastar's eye and his voice, and put them clasped each into a hand, and cast them into the fires. Even as the smoke engulfed them Nastar turned into a black blur and shot across the flames, going out to the world of Aerykun's exile.

***to be continued***