When Horo turn the age of 79, which was practically still like an infant in the cultivation world, he was already notorious for his deeds and knowledge. His deeds and discoveries led to drastic changes in the Eternal Heaven Realm , mostly good but due to greed and envy one discovery turned out not to be so good, in fact it led to the demise of many notable figures, greats clans and even some emperors.
This Tragedy was called the Sin of the Heavens's Eye, the end of the prosperity of the Heaven's Eye Clan.
At that same age is when the feeling of calamity he always felt deep inside him intensified to the point it that it made his dreams and visions urge him to just prepare for his next life which he wasn't even 100% sure would exist in another reality, and to not fight against the flow of events that were to happen in this reality. He did have visions of future related events but didn't act on anything that would change the course.
Even though Horo was once a great figure, and even one that everyone thought would be deemed the greatest from his lineage, he was blamed for the rebirth of the sinners.
The sinners were a group of beings that existed in between the Immemorial era and chaotic, back when the 6 realms were one and the well of reincarnation hadn't even been created, there was mostly chaotic beings and ancient races that exist during that time and the sinners were such chaotic beings, they were born from chaotic energy and an aspect such as sin that existed in physical form in the reality of the cultivation world back then. They were the incarnation of sin, and their progenitor produced the heart of sin which created the 7 deadly sins and so on.
Even though the seven deadly sins existed only as aspects now in the demon realm, the physical form of them was lying dormant in a fragment of the Heart of sin which was discovered by Horo. As always he studied it and even experimented on it to see what benefits it had and discovered that he could use the power of sin to empower treasures but that's all he was able to discover before tragedy approached.
As Horo became more and more glorious over the years his older brother Taji, began to have negative emotions towards him even though they were so close growing up. Jealousy kept growing and growing inside of him until the fragment called out to him, it had sense the great envy he held towards his younger brother, and after luring him to Horo's laboratory it tricked him to make a false contract with it which actually led to the original deadly sin envy to incarnate through him.
The Sin of Envy caused so much havoc and even influence demon kings into infiltrating Eternal Heaven with the enticement of the sins.
Envy revived an army of sin soldiers and helped two demon kings become incarnations of true sin, well one because the demon king of pride was able to take in the power of pride without his soul being devoured, instead he became the original sin.
In the end the Eternal Heaven Realm payed a heavy price in order to receive help from the Spirits realm and Buddhist, the Sin of lust that took over a demon king was sealed in the Eternal Heaven Palace, and the other two original sins escaped to the demons world in order to try and achieve their previous heights of power and get revenge on the 3 realms.
As for the price that was paid…
The Buddhist realm kept the fragment, the immortals world had to open a gate so spirits could freely enter the spirits world if they wanted and not be enslaved by the immortals just because they were born in Eternal Heaven Realm, and the Heaven's Eye clan had to be executed for the gravity of the sin that was committed, the executioner was Horo himself, the supposed main perpetrator. A special scripture and mark was made by the Current Eternal Heaven Emperor, the Bodhisattva Guanyin and the Spirit Lord.
The Scripture was to allow one to bear the sins of all slain by the person reciting the scripture. The mark absorbs most of the person's essence including blood essence, soul origin, and divine will. It then turns that essence into an execution essence blade.
This was done in order to kill the sin soldiers because they were nearly impossible to kill which was why they were sealed to begin with. He was forced to use that same blade to execute the sin soldiers, demons, criminals that were involved in the demons' infiltration and even his own clansmen.
The three supreme realm lords decreed that the only way to atone for his sins was to bear the sins of all whom he was to execute. The mark forced Horo to execute and recite the scripture before every execution to allow the mark to absorb the sins of each individual while the blade strikes their essence severing their soul, will, bloodline and even their karma.
The pain he felt in his heart as every single member of his lineage including the children and babies we unalived by his own hands. This caused the mark of sin to shine as bright as a sun for centuries as he was forced to execute criminals… until his existence was forfeited.