Once the Core had truly accepted him, it merged with his soul more than with his body. It was as if this was something that had been with him from eternity. After accepting the core, Lucifer finally felt as if he was completed.
Unfortunately, at the same time, he also felt more heartbroken as he understood many more things that he previously didn't. He recovered a small fragment of his memories that he himself didn't know previously. It was the memories of the day of his last birthday, before his entire clan was annihilated.
Heartbroken, he dropped to his knees. This core... It was something that only the Master of the Ancient Clan could use. His father was supposed to possess it, but during his birthday celebration, his father had transferred this core to him.