The Royal Contract - Chapter 13 - Speedy Escape

Aaron, a wildlife biologist, became a military strategist right after a global war between nations began.He never wanted to participate in the war but he had to, because he wanted to continue his studies on endangered species the moment the war was over, but to his surprise, everyone in his unit were killed, including him, and the next thing he knew, Aaron woke up in the body of a young noble having a similar name to his.However, he also noticed he had awoken in a world different from Earth.In this world, demonic beasts ran rampart with only one thought in mind, causing them to feed on anyone they see, be it humans, elves or even magical beasts as well.During his first encounter with a magical beast, Aaron awakened a system which allowed him to bond with magical beasts and to obtain terrifying abilities from these bloodcurdling magical beasts, so he used his experience as a wildlife biologist to help make it easier for him to bond with these beasts.However, Aaron also noticed he could evolve these beasts if their loyalty towards him had reached a certain level, so he vowed in his heart to grow strong enough to protect those he cared about in this world with the hope of living a happy, peaceful life where he'll be able to focus fully on his passion as a wildlife biologist.

Julietta, born as an illegitimate child of a nobility, is raised in an opera theatre to hide away from the eyes of the noble’s main wife.

“Missus, time to fulfil your duties!” Mu Yuchen demanded as he pulled Xi Xiaye closer with his arms intimately wrapped around her waist.

It was a meticulously planned feast for the powerful. Her fiancé had knelt down on one knee and proposed to her sister instead. Robbed of her right to her inheritance, she was prepared for the Xi family to throw her to the wolves.
As she slipped away from her family that had turned their backs on her, she found him — Mu Yuchen, the low-profile and reserved noble that ruled City Z and led Glory World Corporation.

“Mu Yuchen, let’s get married!” He looked up at her, then suddenly stood up.

“Where are you going?”

“Let’s go. Any later and the civil affairs bureau will be closed.”

- Description from Novelupdates

It was supposed to be a perfect deal in which both parties got what they needed. However, after the child was born, he tore up the agreement with discontent and told her, “Who said that we’d only have one child? I want twins! Twin brother and sister! You’ll continue giving birth to more children until you bore me a pair of twins!”