The Crown's Seduction - Chapter 26: Birds of the Same Feather

Bound together by an imperial arranged marriage, Li Yuyan is scorned for her association with the ill and blind crown prince. Publicly, she stands up for the seemingly gentle and perfect prince, and he in turn protects her from criticism. Privately, she contemplates inheriting a fortune if he dies, while he considers eliminating her if she steps out of line. Unknown to all, the beauty and brilliance they keep hidden will unveil. During their wedding night, as she cures his blindness and cold ailment, but not his secret illness, she discovers the deceit. Realizing she's been tricked, she tries to flee, only to find herself trapped by him as he expresses his fascination with her.

Childhood sweethearts.
The most popular person in school is my childhood sweetheart.

- Description from Novelupdates

Luis, a poor 17-year-old boy, tries his luck at becoming an Awakener to change his fate. However, his dreams are shattered when he fails to awaken a Special Spirit and is instead saddled with a 5 million dollar debt by their planet's colonizers, the Flying Star Empire.His life seemed doomed—until a mysterious system suddenly appeared in his head: The Monster Transformation System. It gave him the power to transform into any monster or animal he had ever seen.From a cat to an eagle, even a horse, Luis begins to understand that his power may not come from Spirit... but from the ability to become any monster.