Just wanted to point out some twisted psychology.The perception of doing something 'wrong' is usually up to the individual. For instance, I know speeding is wrong because the law says it is, however deep down, I don't BELIEVE it's wrong since I don't believe it hurts anyone else, as long as I am careful.
The point is that most people when they do something 'wrong' either don't REALLY believe it's wrong by their own standards or justify it to themselves so that it seems 'right.' AKA - I know speeding is wrong, but I really need to get to work on time or I'll get in trouble. These are special circumstances, so I'll just do it this once.
Getting this convoluted tangent back to Warren - Warren's reaction to being with Katrina was "I missed you and you never should have left me." It's possible that in Warren's mindset, it was 'right' that he and Katrina be together, no matter what he had to do to accomplish this. In his eyes, they belonged together. I'm not going to debate that Warren's idea of love isn't sick, twisted and selfish - but I don't believe his ONLY motivation was sex. In HIS eyes, he loved and needed Katrina. Again, his definition of the word 'love' is digusting, but I do believe he means it when he says it.
I don't think Warren ever intended to share his new slave with anyone. I believe he uses Jonathan and Andrew to help him achieve his own ends. Warren is using them. The irony is that Warren HAD a slave - the buffybot and he grew tired of her because she was too compliant. Then he turned Katrina into a human version of the Bot.
And then there's Willow...
I'm going to compare what Warren did to attempted rape and what Willow did to theft. Willow stole something from someone that loved and trusted her. It was a violation. But Willow did not compromise the whole of Tara's will as much as she manipulated a portion of it. In both cases someone was trying to fix someone else to their liking. But Willow did not force her will on Tara. Instead she stole something that caused Tara to make different decisions.
The scary part is the serious line that Willow crossed in her own morality at that point. She had SEEN Tara go through the Glory situation and yet she cast the 'forget' spell casually. At the time, she didn't see anything 'wrong' with it because in her mind it was not the natural state of order for Tara to be angry with her. And then...SHE DID IT AGAIN. Even after UNDERSTANDING that what she had done was such a severe violation. She tried to do it not only to Tara but to Buffy as well.
It goes back to the "That may have been how it started but you are fixing things to your liking now, including me," ideal. Willow of old did always try and use magic to help people, but this season I believe Willow had grown both thoughtless, arrogant and selfish with her magic use.
The scene with the club comes back to me. Willow and Amy were manipulating people's will all over the place, and never once did Willow seem to consider that any of that might be wrong.
How far a jump from selfish and arrogant is it to evil? We consider Adolph Hilter an evil man, but in his eyes he was trying to aid the german people. And at the time, he DID aid Germany into becoming a powerful world power and into a more stable economy. He did it because he believed that Germans being superior was 'right.'
It's a bit off the wall comparing our Willow and Hilter, so I am going to stop that. I was only using Hilter to get back to the idea of how people can convince themselves that what they are doing is 'right.'
Assume that Willow had never stopped using magic and it's now one year later. Let's say that she is in danger of totally losing Tara. Tara is leaving Sunnydale or Tara is dating someone - how far would Willow go to make things 'right' again? Especially if Willow believed - as we all do - that Tara belongs with her?
I think Warren is something Willow might have become. They both are techno nerdy, both are powerful, but are intelligent and have a strong will. They both seem to need acceptance.
But Willow was not so far gone that when Dawn got hurt she didn't accept responsibilty. Warren IS too far gone.
Certainly before Dawn got hurt, Willow was far from stopping her pursuit of the dark arts. Katrina's death could have been the Trio's wakeup call much like Dawn's accident was for Willow. It wasn't. (Except maybe for Jonathan) As things stand right now, there are clearly fundemental difference between Warren and Willow. But power is seductive and there is no doubt that Willow was/is very powerful and becoming more so. I wonder if the accident with Dawn hadn't happened, how many lines would Willow have eventually crossed in the name of 'fixing' things. I believe that repeated use of black magic in that way, would have eventually changed the core of who Willow is. I have to admit that I am glad I didn't have to see that journey.