Choosing the right tenth tier spell was a lot harder than it should have been. Like most MMOs, Yggdrassil was designed with the end game in mind, the game really got good when you got to max level.
Part of that was in sheer panache. The dedicated high level players demanded complex and 'kick ass' magical effects that really let them live out their roles.
As such, there were a multitude of spells that Ainz had at his disposal that were death focused, and all of them were just… wonderful.
His flight spell carried him over the world and with his 'detect death five', it was easy to find where the greatest amount of slaughter was taking place.
The beastmen were paying very little mind to him, predictably, considering it a mere trick from some human magic caster somewhere, most likely. 'I can't really blame them for not believing me. But still, they cannot say they were not warned!' Momonga thought, and then it hit him.
'I really don't feel anything about killing these creatures? Back in my world I wouldn't even have killed a pest without feeling a little bad about it. I didn't even use lethal mouse traps. Plus that dramatic moment was out of character for me…' Momonga's thoughts were interrupted by the noise down below.
There were thousands of humans forming up a deep defensive line arrayed with spears bristling like a hedgehog's quills. Behind them stood a string of archers, many of whom were bloodied and weary.
Across from them, not one hundred paces away, was a line of beastmen who were reforming their own lines before preparing another charge. Between the two forces lay a no man's land so thick with dead that Momonga was sure he could have walked between the two forces without ever touching grass.
Most of that carpet was composed of humans, but here and there, a beastman lay fallen, surrounded by his victims.
On the human flanks, cavalry were arrayed who were no better off, though they had good armor and horses, it was clear that they were exhausted, most of them had broken lances, and those who had bows instead had nearly empty quivers.
Behind the humans lay a small town, larger than Enri's village, this place had an actual wall, albeit wooden and only two or three heads taller than the tallest of the beastmen. A garrison of archers lined the walls and from within poured small numbers of civilians holding supplies for the host, racing toward them holding spears, javelins, and replacement arrows.
Still, despite their efforts, the army of twenty or thirty thousand humans was the worst for wear, and even though at best estimate, Momonga only counted about five thousand beastmen… the end seemed preordained.
'Preordained at least, until I got here.' He chortled to himself and used his projecting voice. "Did I not tell you to depart?!" He bellowed and leveled his accusing finger dramatically toward the beastman host.
Heads tilted up from both armies to stare and gasp. 'I hope they can't tell I'm wearing a skirt under these robes…' The idle thought came and went, and Momonga selected a rare spell. [Death Mimic]. This one was unique to not just 'necromancers', but specifically doppelgangers who specialized in necromancy.
This spell turned the dead into whatever killed them and brought them back to fight their slayers one last time. Human became boarman. Human became bearman. Human became pandaman. Human became tigerman.
All of them undead. The blue circles swept and swerved above and the blue glow flared with one last blast of magic power before the unholy roar of thousands of undead froze the beastmen army with horror.
The oppressors were now the oppressed.
The predator was now prey.
Some of less than stout heart, struck by the instinctive fear of the undead, turned and ran for the dubious safety provided by distance.
Others no less afraid but less sensible, simply froze where they stood.
And a few struck postures for battle…
For all the good it did.
The undead beastmen raced over the field, their already strong bodies were not the monsters of monsters, and they tore into the flesh of the living. The flow of blood resumed as a barrier of undeath protected the human host, which could only look on in dismay as a god seemed to have descended from the heavens to rescue them.
Some collapsed into the grass and wept, others began to scream their secret prayers uttered in fearful nights up toward the heavens, hoping their rescuer would hear them and be pleased.
Others, like the beastmen, were simply frozen in disbelief at their sudden deliverance.
The smell of blood rose and the dying became undead, their hunger and swelling ranks added to the confusion as those at the rear and those at the fore became entangled whenever courage broke and the survivors who could see the impossible, nightmarish miracle, turned and ran.
Momonga only stood and watched, calling a halt the slaughter after a mere thirty minutes, his booming voice trumpeted over the field. "Hold!" He demanded, "You who survive are given your lives that you bear this message. Tell your comrades to go home, and never return, or this army will feast on your blood and flesh and bone, from here to the farthest borders of your nation, and not even your children will survive to weep for you!"
There were fewer than one hundred beastmen alive, clustered at the far end, just minutes from what would have been their final stand, around them the recently dead were rising to stand among their killers, and the beastman mimics stood still, growls and stares from hungry and hateful eyes would not turn away from the meal presented to them.
But one among the beastmen who still lived at least had some courage and will left to speak up.
"What gives you the right to deny us this way?! We are beastmen, and this is the pen from which we eat!" The lionman bellowed, his comrades yanked their heads around to stare at him as he threw away their chance at survival.
Momonga however, felt indulgent, even grateful for the chance to use a fine closing line. "I am the strong. You are the weak. I decide where you can eat, or whether you can starve. If you want to argue?" He waved his hand, and the undead horde took a single step before he closed his hand into a fist and they halted again.
"Now run!" He shouted and swept his arm out to point toward what he hoped was the border of the Beastman Kingdom, and the survivors, unwilling to risk the loss of their opportunity a second time, turned and fled.
The lionman, to the credit of courage or madness, shook his fist in futility up at the magic caster in the sky, then turned and ran, chasing his comrades until they were well out of view.
Only when they were gone out of sight did the human army respond, and when they did, it was a cheer that shattered the sky.
Momonga however, noticed only one thing. 'My inner chuunibyou is really asserting itself lately… that can't be a good thing.' He thought, and then as the humans lowered themselves to the ground to bow in subservience, he too descended, ready to meet them in person and enact the next stage of what passed for his plans.