My Master Regrets Killing Me to Prove His Dao

[2v1] Cold, aloof, unhinged master top / Violent, wanton teacher top X Reserved, devoted, homemaker-type disciple bottom

Everyone knows that a thousand years ago, the head of the Sword Sect cultivated the Ruthless Dao to its peak, killed his wife to prove the Dao, and ascended to immortality.

When his friends heard that Cheng Ning was heading to the Sword Sect, they all urged him to be careful with his life.

Cheng Ning waved them off. He was there to find someone.

During last year's heavy snowfall, someone helped him up from a street corner and brushed the snow from between his brows.

Cheng Ning remembered the cloud patterns on that person's clothes and followed the trail all the way to the Sword Sect.

It turned out that the person was Jun Biechen, head of the Sword Sect and the foremost figure among the immortal sects.

Knowing full well he shouldn't fall for a cultivator of the Ruthless Dao, Cheng Ning fell in love with Jun Biechen at first sight. He was willing to become a lowly servant just to stay at the Sword Sect.

The cultivators all thought highly of themselves. None of them had ever seen anyone as shameless as Cheng Ning.

Only Jun Biechen, aloof and detached by nature, went against all precedent and took Cheng Ning as his disciple.

On the night of the apprenticeship ceremony, Jun Biechen, usually as cold as snow on a mountain peak, unexpectedly teased him, calling him his beloved disciple. He pulled Cheng Ning upright and wrapped an arm around his waist.

After a night of passion, Cheng Ning woke to find Jun Biechen back to his usual icy self. His sword slid from its sheath. "I never so much as touched his robes, yet you made me break the Ruthless Dao."

The sword wind swept toward him, and Cheng Ning suddenly remembered everything. He was the wife who had been killed a thousand years ago so her husband could prove his Dao...

And the man who had smiled and called him his beloved disciple was Jun Fuzhou, Jun Biechen's inner demon: the one who humiliated and forced him in private and wantonly used him.

Cold, unhinged / a saint with private desires / master top Jun Biechen

Violent, wanton / a scoundrel with a true heart / teacher top Jun Fuzhou

1. The master, Jun Biechen, and his inner demon, Jun Fuzhou, will eventually separate into two bodies.

2. Older master-disciple pairing. Both tops are masters/teachers, and both will bring the heat.

3. Both tops are devoted to the bottom in body and soul, and both are sexually pure. They take turns in the spotlight, with one-on-one pairings at different stages. Happy ending.

4. Includes a false-substitute trope.

Theme: A teacher's example is more important than their words.