Return of the Swallow - Chapter 505.2: Denouncement

In a world where summoners wield the power to call forth vampires, elves, angels, demons, and all humanoid creatures from across the realms, Nathan found himself unable to summon beings except from beasts. However, those beasts are not ordinary beasts. They are divine beings who once stood at the same level, if not higher, than the legendary creatures the world ever knew. Casting his gaze to the left, Nathan sees numerous summoners accompanied by the likes of demon kings, archangels, vampire progenitors, and other legendary beings. Turning to the right, a massive army of alien symbiotes is waiting to attack. There was no fear in his eyes, because standing on his left is a majestic wolf who managed to kill a god, the legendary eight-headed serpent coils on his right, above him is the bird who is glowing like the sun, and behind him is a dragon that once gnawed the roots of the world tree. “Let the war begin.”

I didn’t know this was a world inside a game. And I didn’t know my master was a mid-boss. “No way… wasn’t she supposed to self-destruct because of her personality?!” …I’m sorry.

Champion dream of an e-sports boy!
Champion dream of an e-sports boy!
Champion dream of an e-sports boy!

- Description from Uukanshu

To treat her sick brother, she was forced to marry him in place of her cousin, who was disfigured and paralyzed. At first, their relationship was purely transactional, with neither caring much for the other. But after going through a lot together, they fell in love with each other. He doted on her deeply.She was considered an ordinary person by the world, but it was later discovered that she had multiple identities - a mysterious underground boxing champion, a highly-skilled doctor, and a mysterious and renowned composer... He also realized that their fates had been intertwined long before they met.