Spoiler Alert!
“Your reign ends here, Lufas!”
The hero Alioth swings his huge sword at you.
“Fools, it is your end.”
With a blast of magic, you push your opponent away.
He recovers in an instant and swings again, striking you in the chest and momentarily stunning you.

“NOW!”
Nearby, the elf sage Megrez calls out, “Hyperspace Seal!”
A sphere of black energy engulfs you.
“Well done, heroes! You’ve surpassed me and I wish you the best against the Demon King!”
…
In Exgate Online, players create their own kingdoms and fight each other on the fantasy world of Midgard, with victors gaining control of the losers’ territory. The company running the game records these events and incorporates them into Exgate’s in-game backstory, publishing it online like a web novel.

Your avatar in this game was Lufas Maphaahl, a beautiful, black-winged flugel, a winged humanoid descended from angels. For years, you’ve trained her up to Level 1,000 in a wide variety of classes, earning top player rankings. You’ve also collected and tamed a dozen rare monsters and event bosses, gathering them into a group known as the Twelve Heavenly Stars. They’ve acted as your loyal companions and generals in the game.
As Lufas, you were the first to conquer all of Midgard. As a result, Lufas gained semi-canon status in Exgate’s backstory. With no more challenges left in the game, you gathered seven other players and organized an event in which their characters would fight Lufas in a decisive battle.
And she was just defeated and sealed away.

The viewers must be going wild, judging from the comments in the sidebar.
The event was successful!
Well, time for bed…
…
The next morning, you turn on the computer and prepare to play Exgate Online again.
What’s this?
On the login screen, you see Alovenus, the creator goddess of Midgard and mascot of Exgate Online, along with a new message.

Is this a reward from the game administrators? Sounds fun!
Yes.
…
Unh…
W-where…? What just…
“Did the summoning work?”
“It can’t be…”
“She’s still alive?!”
“No, no…not the Black-Winged Overlord!”

As your vision returns, you find yourself standing in a throne room.
Why is everyone shivering and kneeling on the floor? Did they see a ghost or something?
Hmm? Your chest feels a bit heavy and there’s something moving on your back.
Something’s missing from your crotch…

You catch your reflection in a nearby window.
It’s…Lufas??!!
A Wild Last Boss Appeared! (野生のラスボスが現れた!, Yasei no Rasu Bosu ga Arawareta!) is a web novel, light novel series and manga written by Firehead (炎頭 [ファイヤーヘッド], Faiyāheddo).
Without warning, a high school student suddenly finds himself in the living, breathing body of his game avatar, Lufas Maphaahl, in the actual world of Midgard by those who were trying to summon a hero. She flies to her old home base and finds Dina, a mysterious young woman who claims to be her advisor.

Lufas learns that events on Midgard played out more or less the same as Exgate Online, with her conquering the world and being sealed away by the Seven Heroes 200 years ago. The Heroes founded their own kingdoms and fought against the Demon King, who defeated them but spared them. The demons conquered most of Midgard after that, leaving humanity and the other races in constant peril. In addition, the Twelve Heavenly Stars are still alive and scattered throughout the land, with some of them now causing trouble. Lufas decides to not only recover her former companions but also talk to the surviving Seven Heroes in order to learn more about her predicament.

Two of the surviving Heroes are found to be wallowing in despair, deeply regretting their victory over Lufas. Before that fateful battle, their minds were gradually filled with irrational hatred, fear and envy, only for those feelings to inexplicably disappear afterwards. The black-winged flugel eventually meets the Demon King, who tells her that the goddess Alovenus is playing a pernicious game of balance in the world of Midgard, preventing any one faction from establishing dominance. The goddess saw Lufas as a threat and subtly influenced the Seven Heroes to fight her despite the fact that she was the only being the demons feared, thus allowing the conflict and suffering to continue. Even now, it’s likely that Alovenus holds an insidious sway over all.
Meanwhile, Lufas’ summoners have succeeded in summoning a hero from modern day Japan, commanding him to defeat both the Black-Winged Overlord and the Demon King. It is also revealed that Dina has been less than forthcoming about her true identity and intentions. Since a human soul now inhabits Lufas’ body, where is her real soul now?

Main Characters
Lufas Maphaahl, a flugel, the one-time Overlord of Midgard and a former male Japanese high school student. Proud, charismatic, honorable and assertive, she has a hidden gentle side and encourages others to fight for what they believe in. Lufas is seen as many things by the various peoples of Midgard: hero, villain, savior, tyrant, conqueror and much more. As the human soul within her gradually uncovers more of her memories, she gains access to more her former abilities and power. Such memories include those from Lufas’ childhood, during which she was cruelly abused by her own father and the other children for her black wings, which are considered a sign of grave sin among white-winged flugels.

At Level 1,000 and with god-like attributes, Lufas is one of the most powerful people on Midgard, comparable to and feared by the Demon King himself, who claims that this isn’t even half of her power in the past! Like other flugels, she has a long lifespan (over 1,000 years) and the natural ability to intimidate others, including monsters, into submission with her voice alone. In Lufas’ case, she could terrify entire armies! Among other things, Lufas is a monarch, a general, a warrior, an alchemist, a mage and a monster tamer. Eventually, she accidentally rediscovers her unique ability to create golden apples, items that give their eater an artificial boost in power (experience points in game terms).
Dina, Lufas’ enigmatic half-elf advisor. Although seemingly humble, helpful and unassuming, she is much more cunning and secretive than she appears to be. In Exgate Online, “Dina” was a background decoration for Lufas’ home base. This identity is adopted by a mysterious woman who claims to have once been a beta test player for Exgate Online. She also sometimes takes the identity of Venus, one of the Seven Luminaries, an elite group of demons. Despite knowing all this, Lufas keeps her around. Secretly a Level 1,000 character, Dina is particularly skilled in teleportation and mind manipulation magic. Curiously, Alovenus is the only other known being who can manipulate minds…

The Twelve Heavenly Stars, powerful monsters tamed by Lufas. Most of them are extremely loyal to and violently protective of their mistress. Members include Aigokeros (a goat-headed demon), Aries (a gigantic rainbow sheep), Karkinos (a giant monster crab), Libra (a mechanical golem maid) and Scorpius (a giant scorpion). All of them have unique abilities and can take on human form if needed.

Sei Minamijuuji (南十字 瀬衣, Minamijūji Sei), a 17-year old former Japanese high school student and a summoned hero. Like many classic isekai heroes, he is brave, humble and virtuous. His role model is his father, a police officer who taught him the importance of not only helping others but also doing the right thing even when everyone else disagrees. After he witnesses a conversation between Lufas and the Demon King about how the goddess Alovenus is manipulating the entire world, Sei begins to have doubts that the Black-Winged Overlord is the evil monster she is reputed to be. Although currently a rather weak fighter, especially compared to Lufas and her allies, Sei is believed to have the potential to become extremely powerful in the near future.

Personal Thoughts
There’s quite a few mysteries in this story that we’d love to have answers for, such as why the goddess is harming the world, why much of Lufas’ memories are missing and who Dina really is.
The heroes’ mission in this story is to confront the true source of the world’s misery: the goddess who supposedly protects it. Aside from most people refusing to consider the idea that their savior is actually responsible for their suffering, Alovenus is also capable of influencing minds anytime and anywhere, with the implication that free will may not even really exist. In addition, she can enhance the power of anyone who submits to her, resulting in them becoming overwhelmingly powerful monsters that exist only to do the goddess’ bidding. Lufas’ resolve to fight the goddess despite near-impossible odds, even for her own incredible power, is nothing short of true heroism.

The idea of a deity manipulating an entire world to ensure the continuation of violent conflict reminds me of the Legacy of Kain video game series. The main villain of these games, the Elder God, manipulated mortals to spread conflict and suffering in order to perpetuate a vicious cycle of life and death to feed and empower itself. It is possible that Alovenus has similar motives or maybe she feels that life without conflict is meaningless. Like the games’ hero, the vampire Kain, Lufas is a villain on the surface but she fights a greater evil who manipulates everything from the shadows.
In the end, the moral behind this story is about doing the right thing, especially when others try to convince you otherwise. If everyone was jumping off a cliff, would you go too?
Moral
Sometimes, doing the right thing isn’t easy, but it must still be done.