MTL - My Koi Sister is Three and a Half Years Old - Chapter 373 Use your body to mend the barrier

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates

Gu Xingshen! Your sister grabbed my man, you helped your sister grab my man! Your family is not anything good!

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

During the first known year, a magical mountain descended into the world from the realm of the Gods. Carved on this enormous mountain was a message: ‘Heaven Prevails’…

After the Grand Descent, a name that was given to the descending of the mountain, the Three Great Sages made their ways to Mystic Mountain where they learned to harvest what we now call magic, establishing the Mystic Cults and eighty-one sacred shrines to help aid mankind with the cult’s mystic powers against the eternal fight to the death with demons.

- Description from Novelupdates