But he said Wan Shin Tong told him he had a visitor. That implies he told it himself, and when we see Wan Shi Tong leave Jinora, he took off flying. I think it's just a simple case of Occam's Razor here.
RaidenRadio wrote: He promised Wan Shi Tong the contents of the entire north pole library to his collection for his assistance.
Is that something that was actually confirmed, or are you just quipping?
Otherwise, Unalaq implicated that he wanted to usher in an age of Spiritual domination of the Earth. Wan Shi Tong may not like war, but he also proved to not understand the nuance of a war for defense versus a war for conquest, so it is possible that he might not have even realized that Unalaq was going to war to accomplish this. Or he might not count a Spirit conflict as "war."
We don't know why he hated war in the first place. It may have been as simple as that he felt it was an insult to use his library as a tool for personal glory. The fact that Vaatu was technically the one in charge also may have helped. I don't think that the Dark Spirits bother him much. It seems weird to us, but it's normal for Spirits to turn dark.
For a being who knows 10,000 things, there are a lot of things that Wan Shi Tong doesn't know. For example, when a group of kids are lying to his face about not wanting to use his knowledge to win a war. Or that radios are not devices with tiny people in them. If kids can fool him so easily, a master of deception like Unalaq should have no trouble doing so.
Avatar Steve wrote: For a being who knows 10,000 things, there are a lot of things that Wan Shi Tong doesn't know. For example, when a group of kids are lying to his face about not wanting to use his knowledge to win a war. Or that radios are not devices with tiny people in them. If kids can fool him so easily, a master of deception like Unalaq should have no trouble doing so.
Actually, he did show up at the end of the episode & say that he knew they were up to something, because they were terrible liars.
Also, as I've said before, he knows 10,000 things, but reason is not 1 of them.
I note that Sokka actually shouted out his intentions loud and clear before Wan Shi Tong attacked... Quite possibly Unalaq started out okay, maybe even helped out spirits a bit. Aside from fusing with Vaatu and being evil and all, he must have had some measure of spirituality in order for Wan Shi Tong to like him. Perhaps it was as simple as wanting to talk to him; everybody comes for the library, but nobody seems to come for the spirit. It's possible, folks, that Wan Shi Tong was flattered into trusting Unalaq, sans knowledge of the Dark Avatar plan. Of course, there are all the Dark Spirits floating about, but hey, nobody's perfect, right?
Wan Shi Tong may have accrued much knowledge in the world, to the point where the sum of information is unmatched by perhaps even all the world's other repositories put together, but Wan Shi Tong's application is lacking. He has shown that scrutinising is not his strong suite. While he correctly deduced that Team Avatar was not being entirely truthful, he failed to pick up Admiral Zhao's deceit, and never questioned the incorrect information regarding the nature of the radio.