questionable taste in accessories

Surely you don't mean the pointless hand ornament? How dare! I mean, yes, pointless, but come on, it goes with the hair. ;-) (I... have actually looked for a hand ornament like that. Do not judge me. *g*)

Anyway: Wig Boy is my favorite antagonist, too! He is actually more competent and effective than it might seem from his over-the-top posing and pouting. He has Style. And he is absolutely, unflinchingly loyal to the end. I give him some credit for being willing to die for his hero and his cause, even if he did choose someone who absolutely did not deserve that kind of loyalty or sacrifice.

Clenched fist of emo.

LOL, yes! He is indeed very emo. In fact, his melodramatic emo ways honestly grew on me. ;-)

How different would his story have been if the Black-Cloaked Envoy had sat him down for a talk?

To me it seems likely that Zhu Jiu had psychopathy issues from the start, and Ye Zun only hooked into them rather than creating them wholesale. So at the point Zhu Jiu actually meets the Envoy, even a good long talk with him very likely would not have helped; he had decided that he was hard-done by at this point, and that he was not going to take it anymore, and had already started down a path he was not willing (or perhaps able) to diverge from. I'm pretty sure that no matter what the Envoy could have said and done at this point, it was already too late.

Now, if the Envoy had arrived on the scene earlier, before Zhu Jiu ever met Ye Zun. I think it was inevitable that he would find an ideology to seize on and become a violent radical in some way or another - but he might have found a different ideology and hero.

Say, if the Envoy had defended Zhu Jiu against his captain in some way, or said something in defence of the powerless Dixing people - perhaps that they are just as important and valuable as those with powers, and have just as much to contribute... maybe then, he'd have fixated on the Envoy instead of Ye Zun.

That would have been very interesting, because his basic personality would still not be any better than what we know, even though he's be earnestly trying to do what the Envoy wanted of him.

This ties into your other question a bit - Chu Shuzhi is just a much, much better man than Zhu Jiu in general, so even if they had both been loyal to the same man, they would still have been radically different in outlook, approach and morals. Sooner or later, the Envoy might have had to lock up Zhu Jiu no matter what, because of the collateral damage and general viciousness.

And of course, at some point being constantly corrected and reprimanded might well have caused Zhu Jiu to turn against the Envoy later on. He was never in that situation with Ye Zun, because Ye Zun rewarded his viciousness and he felt validated and important. He would not have felt validated if he'd been following the Envoy, and I think that would have made all the difference.

What made him decide that straggly purple hair and Final Fantasy accessories were a good look for him?

HE IS A FASHION ICON. Do not disrespect the emo!

Could he have been redeemed in the show timeline if he had lived?

I don't think so. He didn't want to be redeemed, and I don't think it was possible for him to let go of the notions he'd seized on at Ye Zun's coaxing.

Does Ya Qing regret his death once she has to work with the master of the Merit Brush?

Oh god yes. So much. He was annoying, sure, but he was still somewhat competent.

You can get that type of hand ornament on Ebay, too - just not like Wig Boy's version; most of them seem to have skulls and other such things on them, which, nah. :-) If you think they might have Wig Boy's version at Mandarake, I will send you a screenshot! (Why yes I do have one, why do you ask? erm. *g*)

The question of psychopathy/whether Zhu Jiu would have been okay if he hadn't come across Ye Zun... it's a good question, and I'm not entirely set on my kneejerk response of "he would have gone bad anyway". But my initial response (which I still consider the most likely) is the result of how he reacts to Ye Zun; that he seems to do what he does in response to Ye Zun's "persuasion" mostly of his own free will, and that he reacts the way he does.

Unlike other people we see hypnotized by Ye Zun later, Zhu Jiu doesn't act like a sleepwalker; he seems to be the master of his own actions (I think Ye Zun doesn't have nearly as much power yet and can't actually control people the way he can later, but that's a different issue). That he accepts Ye Zun's poisonous lies as easily as he does probably does have to do with magic, since Ye Zun's lines are bad enough that he needs magic to make them convincing *g*. But that Zhu Jiu jumps straight to murder in response, and shows no remorse afterwards, seemed to be his own choice to me. A non-psychopath might have begun rebelling more and more, questioning things, rousing the rabble, started radicalizing himself... and might well have ended up in the same place eventually. But to jump straight to murder?

So that's where my impression that he already had issues came from: his near-instant turn-around and the eager - and instantly murderous - way he embraces a leader and a path that seems more rewarding to him.

So, headcanon time: Basically I think Ye Zun has been trying this with pretty much every person who came across his field of rubble, without enough oomph to erase their own will, as he can later. And Zhu Jiu is the one in whom it takes, because he already has the seeds in him. He's the one who takes it to murder and thus throws his life away, dedicating it to Ye Zun through a combination of choice and no other options being left. Meanwhile, the other people Ye Zun whispered to are probably the ones spreading the rumors the Envoy is a traitor... but that's all they're doing. Because they are not psychopaths. ;-)