| Remorse (Season 0; After the 6th Episode)
For the longest time, the spirit had felt nothing but loathing, apathy, and rarely, respect towards the temporary holders of the puzzle. Most people had appalled him to the point where he killed them through the restrains of the puzzle and was done with it. It was only until Yuugi had solved the puzzle did he begin to defer from killing – the young man didn't like violence and with good reason. Being constantly beat up for years would do that to someone.
He didn't want to be someone Yuugi feared. Yet without him realizing it, the years of darkness and constant waiting seemed to manifest as uncontrollable rage whenever the littlest slight was brought upon Yuugi or his friends. The spirit had waited so long for him that any instance of pain or hurt brought to him sent him into a psychotic mood and need to punish those who had wronged those he cared about.
The spirit couldn't bring himself to have Yuugi know the horrors he would dish out against others; so he would knock Yuugi out when taking over. All Yuugi needed to know was that what used to bother him wouldn't do it anymore.
Even still Yuugi could tell that something was going on and it hurt him. The spirit did not expect such a development; Yuugi had began to question whether or not he was a bad person because of the actions the spirit took.
It was a, as the youth say now, "wake-up call".
He could not allow Yuugi think he was responsible. He did not want Yuugi to doubt himself even further than he did. The young man did not deserve it - especially when it was not the young man himself causing those punishments. Not when the young man did not even know what kind of soul he now harbored - not even the spirit could say for sure who he had been.
He didn't want Yuugi to be in pain anymore; that's why, the spirit realized, that he had to be better. He had to stop hurting people and most importantly, stop hurting Yuugi.
At that point, the shadow felt remorse.
I seriously like Season 0 because there's just such a contrast between the beginning of the season to the end. In the beginning, I think most will agree that Yami was a real piece of work, some even went as far to call him and his actions psychotic (though whether he's tamer in the manga… *thinks about the burger chapter* I don't think so). However, as the series went on Yami seemed to really dim down that really frightening aspect of him (the yo-yo episode and the crazy teacher episode in the anime, for example) and was more concentrated on outwitting/setting up a simple trap that wouldn't permanently harm the other person.
The reason for this can range from either Yami naturally calming down after finally being released or Yuugi's influence on him. I think that it's Yuugi's influence, but then, I'm a Puzzle Shipper.
However… I think that Yami has a strong sense of justice… or a really convoluted version that essentially says 'You fucked around with me/those I care about, therefore I get to fuck you up/what you did gets to be your undoing'. This is even in the main series apparently (anime at least), as seen at the end of the Pandora duel.
(Spoilers: Essentially, while Pandora is flailing about the saw coming to kill him, Yami just stares at him like 'I could save you, but then again, I could not save you'. It's Yuugi who saves Pandora... and this is Season 2. I haven't even touched Season 3 or 4 yet. I think that alone shows that even though it seems that Yami will refrain from such psychotic punishments like in Season 0, it doesn't mean necessarily he's willing to save you.)