Since logic has been brought up by Doldol as well as others, I will make my point with logic, reasoning, and textual proof.
Let's start by looking at the reason for the demote provided by Doldol in the OP.
Doldol wrote:
While possessing great qualities, it has been a growing issue that he has a tendency to not follow the collective decision by EgN's higher-ups, as well as complaining about what he sees as negative in EgN to non-higherups. Instead of constructively working on resolving issues with the higher-ups. He has been approached and even warned about this growing issue before, his failure to listen to this critique inexorably led to this demotion. (Declined Staff)
1. "it has been a growing issue that he has a tendency to not follow the collective decision by EgN's higher-ups"
Collective refers to the entirety of the staff. I say that, because I have spoken to the staff+ many times in the past, and not once was there ever any mention of Wartheft going against a decision. To go along with that, none of them ever had any anger or resentment towards Wartheft. I know this because at one point I was good friends with some of them.
2. "as well as complaining about what he sees as negative in EgN to non-higherups"
As you have mentioned in the past, this is a community. As a community, I see nothing wrong with "non-higherups" knowing what the problems in the community are. Not only do I see it as our right, but I see it as our privilege. Many of us were given administrative powers because we have proven trustworthy for them. Not only that, but we were voted upon and accepted into the community. So for you to say that him telling us what problems EgN is facing seems quite unreasonable, as there is no reason to hide a problem that we might be able to help fix anyways.
3. "Instead of constructively working on resolving issues with the higher-ups"
From my past talks with him and others, it was evident to me he disapproved of you. The reason he did not do anything, from what I can tell, is that he didn't want to start a battle he had no chance of winning. At the moment, you have control over EgN. Even if Staff+ are supposed to have that same power, you still have that power yourself. The only difference is, you decide who becomes staff+, and who loses staff+. Not the higher-ups, not the Co-Leaders, but the leader. You. So, he didn't tell you that you were bad at leading because, frankly, he has no nice way to say it. If he told you, all he'd do is cause drama. So, he let you have some room to do your job. But, to say he didn't help the higher-ups as a collective doesn't exactly apply. Most of what he does do is administrate the forums, make sure the administrators are set up on sourcebans, the forums, and in-game, and to ensure disputes between members, administrators, and regulars, are dealt with in a former, justified, manner. He does that job better than I've seen any higher-up do in the past few years, which is a long time for a gaming community. As for dealing with higher-ups, which you say he failed to do, that's your job, not his. He doesn't have the power to remove Staff+, and even if he did, he's not really supposed to. Who gets kicked from a Staff+ isn't up to him, it's up to you. So I hardly see what improvement he could help facilitate among the staff+ when his job lies elsewhere.
4. "He has been approached and even warned about this growing issue before, his failure to listen to this critique inexorably led to this demotion."
I actually have reason to believe this part is true, but not fully. Despite how truthful this part may be, I still find it illogical for you to demote him over it, as these are all issues that I don't see him being able to improve, nor do I see why he would need to. The job he was given by Kharn, he does a good job at. I know Kharn agrees, and I know the other higher-ups agree, noticeable by the fact that the majority are backing him up. Regardless of any of that, according to your reasons, you approached him about the matter, no doubt to tell him to do his job differently. I see no possible change in how he does his job that could improve anything. Some may argue that him being nicer is an improvement he should make, but I don't see that as possible when we're talking about Wartheft (No offence). Aside from that, he already does his job the way that's required of him.
I would provide more insight, but you have left us nothing else. You say he went against overall decisions, I would love to see examples, and I know the rest would as well. You speak about him like he was a security issue, which I doubt very much so, since he hasn't done anything bad thus far, and has provided his side of the story on that, which you have yet to comment on. Then, you speak about him as though he's done nothing but cause drama as an Advisor, which is ridiculous, as he did most of the work of the staff+ anyways.
Now, do keep in mind that he makes no money out of this. You are not paying him to be an Advisor, so any time he has put forth towards this community is him volunteering because he wanted to help EgN. If he really wanted, he could have left any time, but he didn't, despite it being obvious he dislikes the way things are run. He showed loyalty, and yet you belittled him over what we can all guess is a personal problem.
In conclusion, your reasons for his demote are no long applicable, or based on anything significant. You can provide more reasons, with examples, and in fact I encourage you do, but until you do, you have no logical or reasonable reason to keep him demoted and banned from Teamspeak. For these reasons, I request you unban him immediately until further notice, as well as reinstate him into the position of Advisor. As a man of logic and reason, I don't need to tell you what the reaction of the community will be if you do not.
As a fellow man of reason, I appreciate you taking the time to read this, as well as what others have posted as well. I only hope you make the logical decision in this case.