Due to most of his essence being turned into the executioners blade Horo's body was practically mortal, the only reason he was able to continue living longer than everyone expected was due to his special soul and body which were one.
Also, due to the mark of sin his soul and origin would perish along with his body, the realm lords didn't even want his origin entering the cycle of reincarnation.
When he was about to fade from existence the guards on the execution grounds witnessed Horo fall flat on his back on the execution platform, and then some form of black energy that they couldn't discern covered Horo's entirety and then it crumbled into nothingness.
A few moments later the Eternal Heaven Emperor appeared which scared the guards shitless because they never seen him appear after the primary executions, and he was releasing his divine sense to figure out what was that energy, but it was bearing down on the guards as well.
He thought deeply while rubbing his chin as if he was trying to figure something out , "that energy, it felt like the nemesis to reality itself, like the black sheep of all energy it, it it felt… it felt like all things negative."
Next he asked the guards what happened, after hearing the explanation he decided to hold the scripture accountable for the weird energy and the way Horo perished.
But before he could truly perish…
"Due to your special Soul Palace your soul has overcome this tragic life"
"Your origin receives all blessings from this life and shall carry them to your true origin."
"Since your soul has overcome this tragedy it allows the Tree of Tragedy to begin its second evolution"
"Your soul bound Tree Of Tragedy has Evolved into your Soul Guide."
"Due to the physical body for this soul perishing the Soul Guide will now take this Soul (soul palace) back to its origin."
The soul guide (evolved Tree of Tragedy) was all connected by some omnipresent connection, so all his consciousness' felt, both of them was an extreme pull and sudden stop that happened in an instant. Next there was more notifications…
"Origin merging with secondary origin….."
"Integrating origin of Eternal Heaven"
"Soul Module evolving multiple times"
"Soul Module gains spirituality and memories "
"Soul module initiating….."
" Your origin has grown tremendously and evolves to an origin body"
"Your soul has grown tremendously and evolves to the soul palace"
" Your soul palace seals most of the strength of your origin to protect your body"
"Your soul palace suppresses most of it's strength in order to protect your body"
"Your Tree of Tragedy is evolving"
"Origin bestowing blessings"
"You have received memories and techniques"
"You have received bloodline trait Heaven's Eye"
"Your Soul gains Heaven's Eye"
"You have received essence execution blade"
"You have awakened skill [ Execution ]"
"You have received Mark of Sin"
After hearing the notification about the mark Horo's eyes shot open, and then..
the sky turned blood red.