Xuanyin, My Master

(Plot-focused, one yandere heroine, slow-paced wish fulfillment. The heroine is stronger than the hero at first, but he grows steadily until he becomes a peak powerhouse capable of protecting her. The opening may be a little slow, but things pick up quickly.)

When Shi Ning was seven, his village was massacred. He was the only survivor.

Just then, a woman passing by, cold and ethereal, with beauty that outshone all others, asked calmly, "Want to live? Then come with me."

To avenge the people of his village, Shi Ning became Xuanyin's disciple. Over ten years of living together day and night, Xuanyin grew less cold toward him, while Shi Ning stopped seeing her as merely his master. Their relationship began to bind them together as if by fate.

And the once aloof master gradually became a yandere...

Later, as an adult, Shi Ning discovers during his quest for revenge that the massacre was far more complicated than he had imagined.

The ancient mirrors came together, and a line of text appeared in an instant:

The Outcast; all beneath him are ants. The creation dares defy its maker, and must be put to death!