[An "alternate" ending to Saiyuki Requiem as an explanation for Go Dougan's current existence]
To the Sanzo ikkou, Go Dougan's life had meant little to nothing. Though it was still difficult for the youkai to comprehend; all they truly cared about was making it to the west, unhindered. In Dougan's mind, he had been overlooked. He was meant to be helpful, not harmful to his master's ultimate goals. But the worst part of it all was the way in which they so quickly recovered, after his supposed 'death.' They were joking and continuing on with their ridiculous argumentative banter, mere seconds after his 'body' had succumbed to Houran's treacherous tricks, and Sanzo-Sama's incredulous, final shot. Even as much as Dougan had begged and pleaded for his life.. having truly wanted to be 'saved'.. his former sensei had pulled the trigger, anyway.
This factor twisted and churned the bile within his gut, as he watched them all drive away. They were all foolish to think that he had been killed so easily, when the answer to this mystery was all around them, the entire time. Dougan knew that the party would not take him with them, from the moment just before he blew the Hyuu Maoh palace to smithereens. There was no reasoning with them, and he had witnessed far too many youkai meet their untimely fates by assuming they had the upper hand. Yes, he had appeared to Sanzo and Goku at first, right after the building had been destroyed. He tried one last time to get his master to agree with him, but it was a fruitless effort. He had to cut his losses, in order to survive another day.
As he disappeared within the water, he swam down into the tunnels that led beneath the dungeons of the burning pagoda palace. This area was safe from harm. He then sent his replacement; a shikigami of himself, that he had imbued with the very same paper plane that Sanzo-Sama had given him in his late teens. He had implanted the talisman in order to make the magic more powerful, for a convenient distraction. The Dougan that would reappear from the water was nothing more than an illusion, just like the ones they had experienced before.. but with a much stronger talisman inside. As the ikkou would be fighting this monster, there would be no way that they would turn their attention across lake, where he would disguise himself with magic in order to watch the whole scene unfold. It was easier to control his shikigami's words and actions this way, as well.
In the aftermath, he was a little bit disappointed that his master had not seen through the deception. There was a very small part of him that hoped he did.. and was allowing Dougan to escape with his life, so long as he didn't interrupt them, anymore. That would be his houshi's wish, if he did continue the ruse for Dougan's sake. Then everyone would have to conclude that Dougan was dead, and Sanzo could have a clear conscious about what he did.
However, Dougan was fairly positive that Sanzo had been fooled. Sanzo-Sama had pulled that trigger, in full knowledge of what he was doing. He was sending this calculating bastard to the otherworld, just like he had done countless times with youkai that he never knew, or cared about. He was nothing to the ikkou, and this fact rubbed Go Dougan in all of the wrong ways.
In the days that passed, he laid low, until he felt it was time to reconstruct the palace. They would not be passing by this place, again. Their goal was westward, and he had missed his opportunity. And yet, he would still plan to meet them again, someday. The approach would not be the same, but he needed a stronghold in which to devise his master plans, and the Hyuu Maoh Palace was just the right place. There was nothing to fear, because none of the clan existed anymore, including the insufferable whelp that had given her life in vain to 'save' the Sanzo party. He was alone in the magical forest, able to obfuscate himself if need be, but there was little need for that. After all, Go Dougan was dead, wasn't he? He chuckled a little bit to himself as he thought on that notion. The chuckle triggered a series of uncontrolled giggles, followed by a deep and maniacal laugh. The world had not seen the end of Go Dougan.