There are a lot of theories regarding him as a whole, many never got to hear who he was before giving himself just the name Doc and what drove him a lot to try and save someone who is destined to die every time he tries to be really unknown. He was a human just a mere human in a very destructive environment until he has chosen this new fate of his but even then he curses this fate as it gave him even more trouble, a constant life loop with no end he tried anything and everything, but he always comes back slowly recovering from his injuries.

The mask he carries is the thing that gave him this life, a skull of sorts with magical properties but also with a soul within it. The info about the mask is that it was created thing from an ancient civilization who were trying to go beyond the universal capabilities and trapped a powerful being in it. In the past, those who had it slowly lost their mind and died their souls being consumed by it, but Doc had a fair game with it which he won, and it gave this new life

In a mission on an alien colony where he has gotten a good relationship with their queen he was trying to find somewhere bouts of the gold dragon the colony was attacked out of nowhere by an enemy he knew all about. Sadly during the fight, the queen died and a collum next was destroyed revealing a gold orb as if he was called to it, he grabbed it and became the gold dragon, and just like the mask it seems it tried to take his body sadly failing becoming one with him after destroying the enemy ships and leaving the alien colony behind.