History: Born During the Dark Age of Technology to a family of traders who were experts at their craft, and passed it on to others, but their best secrets are passed on through the family, especially the one who would be the heir to the company. During one flight, his ship malfunctioned and crashed onto a planet, horribly wounded and dying, but he began to heal his wounds, which was a sign he was a Perpetual (He later found out that his ship was sabotaged by enemies looking to kill him and his family to take over their business)
But, he couldn't celebrate for too long, as the planet he crashed into, was home to Eldar; who saw him healing himself from the deadly crash, and captured him and decided to experiment on him.
But the experiments preformed on him were gruesome, cruel, and even downright unethical, and some even pushed the limits of ethics of Eldar (If they had any at least). After a few millennia passed of these experiments being done on him, he broke out and started murdering any and all Eldar in his immediate vicinity, and began to hunt and kill them. Due to how brutally he killed them, he earned the nickname: Monster of Bone and Blood.
After a few days of slaughtering Eldar later, a group of them came together and were capable of subduing and tranquilizing him and brought him to a different planet, to attempt to kill him, but one of them was capable of convincing them otherwise, but under the condition that she stay on said planet with him as well, which she agreed to do.
After some time passed, he woke up and saw her, and didn't try to immediately kill her, but instead stayed away from her, but after more time passed the two began to talk with one another and she began to see him less as an uncivilized murderer, and more like an actual sapient being who can think greatly. Some more time passes and more Eldar come to this remote planet to check up on the two and see the two of them getting along, one of them tries to kill her, but is stopped by Cryozen before he could even lift up his weapon, and after a lot of haggling, they agreed to study him, and not preform experiments on him.
While everyone else is having a ****** time during The Age of Strife, he is allowed to travel with the Eldar, even through the Web Way, to try and get on better terms with him. And as time goes on, he realizes he gained psychic powers due to the amount of experiments done on him by the Eldar during the Dark Age of Technology, but they were weak, even compared to other Psykers of the time, but he slowly became more powerful over time, and even began to gain the respect of The Eldar.
But not everything was sunshine and rainbows, especially for the Eldar, and him and others, seeing the writing on the walls, got onto a ship and fled the catastrophe, and when Slaanesh was born, Telsya, the eldar who was the first to respect him, wept as she saw her empire crumble(She does get sad over it whenever its brought up, but she also sees it as Karma catching up with the Eldar)
After Slaanesh's birth, Cryozen, Telsya, and the other Eldar with him went from planet to planet, trading with a multitude of different aliens, human planets, and even the occasional craftworld here and there. As the Imperium expanded its borders and became a stronger power, they traded with more and more planets, and dodged the occasional Imperial Ship to continue trading with people.
When the Horus Heresy happened, he continued to trade with Imperial Planets and Xenos, and did bis best to avoid Chaos and its followers, especially since Slaanesh is apart of Chaos, and it loves Eldar Souls for breakfast.
In the Current Millennia, he trades with many people and even with the Imperium itself, and even a few inquisitors here and there, but mostly avoids them due to him traveling with Eldar and his appearance being less than human. He also has begun doing things faster due to the Great Rift, and is completing his plan faster and faster.
His Plan? To let The Emperor come back to life and lead the Imperium once again. He also seeks to wipe out the Dark Eldar, prevent the Orks from WAAGH!!!ing any further,and wants to lead the Tyranids on a wild Goose Chase so the rest of his plan can be done. (He has mixed feeling on the Tau and Necrons, but he seeks to get rid of the Flayer Virus as it reminds of his time as a test subject to the Eldar)