Martial King's Retired Life - Chapter 36Book 15:

In a normal and average modern world where a prestigious academy nurtures elites in a certain field who are known as ”Supreme“ such as [Supreme Inventor], Allen Walker suffers from being called 'average'. Allen Walker can't accept why he has to be average when a few are fortunate to be born as either a genius or prodigy. After a week of self-loathing, when all of his hope was lost, a sound snap him back to reality, or is it insanity?

Ding!

[A suitable host has been found! Prodigy System at your service!]

Ding!

[Hello darling! Chuu~ Harem Protagonist System at your service! Or do you want my service in bed instead?]

Ding!

[A wild Anti-loner System has appeared!]

Ding!

[Fiction fanatic, praise thee and thou shalt be graced with the Multiverse Traveler System!]

Ding!

...

Before Allen can even choose a system, another too familiar sound harassed his ears.

Ding!

[For achieving a thousand system requests which are a one in a decillion chance to occur, a Supreme Being was forced to use Divine Intervention.]

[Merging all of the thousand systems to create the most versatile and advanced system... Merging complete! Alternate Multiverse Chat Group System has been obtained!]

After accepting the Alternate Multiverse Chat Group System, Allen becomes a prodigy and the Chat Group's Admin and has no choice but to chat with beings from other universes.

Beings with suspicious, delusional, and eccentric names such as [I Love Mathematics], [Lolicon Shota Cultivator With Soul Fetish], [Sword Forge From Chaos], [Self-Proclaimed Genius Goblin Hero], [Reality's Bitch], [Time Manipulator Of The Apocalypse], and [Delusional Modern World Chuunibyou]

The chat group introduces Allen as [Supreme Order] as he chats with the otherworldly beings to find out the secret behind the Alternate Multiverse Chat Group.

The world calls for heroes, and in dire situations, they tend to rely on anything just to escape death and live.The story begins when a man from another world becomes one of the three heroes of fate. His strength prospers among the other two, fate favors him, but the people do not.After saving the entire continent from the Demon God, they feared his strength and banished him from any human land with no where to go he thought of nothing but to suffer.But there are still beings who cared enough to give his life a new light.[ You are never Forgotten ]

The fallen ones, strange monsters that showed up on earth with the sole purpose of destroying everything and ruling over humans.Only one man remained during the onslaught, his name, was Rashin Montero.“Do you wish to live or die?”The question appeared before him.“Kill me assholes!”He died.A hundred years passed and Rashin finds himself alive in the future.It turned out he was saved by a stray angel, and was granted a powerful energy that allowed him to stand on equal footing with the monsters that once wanted to take over earth.In his new future, the world has been restored to what it ones was, a huge shield was placed around the world to keep the Hakiaas out.Heroes were summoned to defend the world against these monsters during the Countdown, while the monsters could not be killed or harmed, they could still be sent back to their world.Or at least, until Rashin arrived.[Blacksmith System activated. Welcome host.][Initializing core functions... Complete.][Congratulations, you have gained a new blue paint (Large sword.)][Stella blade has passed all requirements to evolve.][Evolving to human form can now be processed.][Congratulations, you have gained a unique core, your weapons can now undergo fusion.]Having a system that allowed him to craft weapons of all kind, Rashin enters this new world trying to survive while also remembering part of his memories.Not just that, he can also turn every weapon he makes into beautiful overpowered maidens capable of killing the Hakiaas aka fallen ones.

The second prince has come of age. To celebrate the advent of such an occasion, the search for a suitable bride began. My younger sister was expected to go to the Royal Palace as a candidate. However, despite this, she eloped the day before her departure. I, the older sister she left behind, looked almost exactly like her – so much that we were often mistaken for twins…

One month, right? For just one month, shall I substitute in for my sister?