MTL - The Last Cat in the Universe - Chapter 15

I am Master Siwei, and I speak for arcane arts.
This is an era of heroes and heroines.
This is an era of great changes.
In the end, it will be an arcane era opened by me.

- Description from Novelupdates

Perla had always felt a longing for adventure, stifled by the rules of her strict upbringing and surrounded by her older brothers free to do as they wanted. She longed to carve her own path, to seek out excitement and perhaps even a little romance along the way. One day, while escaping yet another tedious piano class, she stumbled into the hollow of a massive tree. At its base, a mesmerizing green light beckoned her, and before she knew it, she was transported to a bizarre forest teeming with colossal, long-extinct creatures and menacing carnivorous plants.This was the realm of Beastkin, where men could transform into mighty beasts. Here, the constant threat of war had led to a peculiar imbalance, with most females giving birth to male Beastkin, resulting in a dire shortage of women. The land was a battleground, filled with mercenaries and adventurers seeking glory. While the males formed companies to embark on quests, their females stayed behind, living a life of comfort. But not Perla—she was determined to break free from the mold, to grow stronger, and to join her new love interests on exhilarating escapades.

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----

In a world where martial artists reign supreme, strength is everything. Unfortunately, that logic doesn't apply to a certain Florida Man.

Refined in the nuclear fallout wasteland, Leo was the strongest mutant alive. He carried an alien artifact, allowing him to exchange his lifespan for modern items. After 50,000 years of solitary life in a humanless world, he collected enough lifespan to transmigrate to another habitable world.

Leo was later thrown into a mysterious planet. He soon discovered that his body produced radiation, and it mutated the surrounding plants and grasses. Worrying that he might ruin the beautiful planet, he chose to live in seclusion.

Unfortunately, the local population soon discovered his existence, and a misunderstanding ensued.