*cOUGH* this will be a long post, but I suppose it might give some insight to things, I wanted to actually make this connection after MR finished all the scanslations, and in my fanfiction, but I suppose Ill write my theories here.
I deeply think that Anna/Yoh/Hao are deeply connected. First of all lets go through the basics:
Hao/Yoh: Yoh and Hao are connected because of a couple of reasons: They are twins, and practically the same person. They are like halfs of each other, and have very similar characteristics and power techniques. Except, Hao has more because well-- he's Hao, and also of his training for 1000 years. Hao is so powerful and his foryoku is such because he was reborn so many times. He uses the Spirit of Fire because he simply likes it, but can control all the other elements as well. Yoh has the capability of just having as much of power, but Yoh's driving force is Anna and others via himself to become Shaman King, that is why when he quits the first time around he regrets for Anna first-- not himself. He thanks everyone, he thinks about others before himself. He wants to make the world a better place for Anna, for everyone. Where people can relax.
Now the thing is, Hao wants to do the exact same thing. he wants to establish equality and create a world where everyone is the same-- hence he kills the weak people and wants to get rid of the humans. He takes a totally different solution to the problem. Now some people might call this evil, but evil is totally bad. Hao isn't totally bad. He has his light hearted characteristics, and lets face it: with the amount of foryoku he has, he could have easily killed some powerful foryoku users and then used them food for the SOF. There is another thing about Hao, he wants someone or a world he can live in where people are equal, he can't kill everyone. Humans killed his mother, so he doesnt like them. And lets say this: Horohoro doesn't like humans that much either, remember why he want's to become Shaman King? Because they destroy nature. They are always selfish. Anna says this too, she says she hates their selfishness. They have something but they want something more. Shamans realize that there are others in the world besides themselves, but humans kill anything they consider as a threat, and at the end solely care about themselves.
So either way, Yoh and Hao are halves of each other. One other thing I would like to note is this: Hao could have killed Yoh and devored his soul long ago. Why didn't he do it? He wants Yoh to get stronger. He wants to be able to face someone like that I suppose? Hao has faced a lot of betrayal in his life. But this is one concept I don't really understand, why he didn't devour Yoh all this time. He insists on Yoh taking part in the SK fight, he also gives the 5 fighters Opacho who he KNOWS has the power of Reishi to assist them in their path through the plants to him. What is Hao doing?
Anna: Anna suffered from the same things that Hao did. She was abandoned by her family, and has very powerful powers I believe. She was saved by Yoh. But let me enlighten something: Matamune was saved by Hao, and Hao trained him, gave him the power that he had, he took care of Matamune, and in turn Matamune gave power to Yoh who saved Anna. So let's step back a bit here, so if we go back to the first chain of events... Hao >> Matamune >> Yoh >> Anna. So Hao >>> Anna. Connection made-- hook, line and sinker XD. There is the first connection of that. Hao SAVED Anna indirectly. Also, Anna is the only person that Hao cannot read the mind of, she has the power of Reishi but he CAN'T read the mind of hers because of this, and she doesn't give him permission to do so. I personally believe that Anna never lost her power of Reishi, but she has it dormant. She doesn't have those feelings and power because she SHARES them with Yoh. But she still has that 6th sense, which someone on these boards mentioned, she says that the spirits told her. Ya right :P. She is hiding it, why? I don't know, same reason why Hao hid his power of Reishi so cleverly from his subordinates. Now here is one thing, does anyone recall ch 245? In the middle of the Anna/Hao fight, Anna thinks in her head "Please Tamao..." (cause she asks Tamao to go get Yoh). Now the thing is this: Hao can't read Anna's mind, but he gets utterly pissed in this. This totally caught me off guard. SO I thought to myself, how can this be?
Yoh's mind can be read. We see this undoubtly in Chapter 251. So that throws off the chances of him having Reishi. Either that, or he is SO lazy and so carefree that he has the CAPABILITY to learn Reishi or use it, but doesnt have enough power or will to do it. He just doesn't. I'm not throwing away the possibility that Yoh has Reishi but doesn't know how to use it, or it hasn't been "activated", just like Anna's power "just disappeared". She can't read minds anymore she tells Manta, but she doesn't know why I believe... The Oni and Reishi get dangerous because you have have all your thoughts built up in one embodiment. That's what causes them. Now Reishi, which some places refer to you as having "1000 worries" you have to not only listen to your own problems but others, now just a long shot here-- but I believe that it is possible, it Reishi is a dormant ability in Yoh and an active one in Anna, perhaps there a connection can be made. Yoh killed that huge Oni at the end of the osorezan revoir, and perhaps at this encounter it became slightly active. He killed Anna's embodiment of all the evils etc, and Anna began to trust in him. Now to go to my grand finale of all this, my theory is this: That Anna and Yoh have a deep connection because they can read EACH OTHER'S thoughts, but not someone elses. But of course, when they read each others thoughts this makes a connection between them. And it explains, countless times that Yoh knows when Anna is in trouble, how Anna knows about Yoh being in trouble and so forth. The most biggest proof would be when Yoh came back from hell and he says that he must hurry because Anna is in trouble, and no one says anything. *phew*
Let's get back to the Anna/Hao fight. I believe that Hao has that connection with Yoh that every twin has. Now the thing is, perhaps Hao can read Yoh's mind right, so it could be the possibility that he doesn't have Reishi, OR that Yoh has reishi but with Hao it doesn't really matter. If my Anna/Yoh theory works, then Yoh can't read Hao's mind, but Hao and Yoh are not just any two characters, they are apart of each other, they are the same person, so why not be able to communicate that effectively, and of course, Hao has much more power to take the head of this relationship to achieve the balance between the both of them. But then again, Yoh and Anna seem to understand Hao the most, with Yoh's constant statements about Hao, one being the one with Hao not having any friends etc.
As for Yoh not being powerful and all, lets say this: What Hao has, Yoh doesnt have, and what Yoh has Hao doesn't have. So if Hao has all the power, then Yoh wouldn't have as much, he would have to build it on his own accord to achieve the delicate balance that underlies their relationship.
With Anna and Hao going back again, I think that when Hao got really mad after Anna's plea to Tamao in her head, it was because he knew what she was thinking. I think that if Yoh and Anna are connected in the way that they are, usually whenever Hao meets up with Anna for important moments he is alone with her. I think this only happened twice, on their first meeting and also in their fight. But by the time 245 came around Yoh was back and he was close enough to Anna that Hao knew that Yoh was back. I think Hao was expecting him back-- since he didn't really show suprise when he saw him the cafe. And when Yoh was coming he intercepted Yoh's thoughts and then to Anna's... And he was mad not because she was calling for him but because of her INABILITY!
Hao is obsessed with equality, he has high expectations of people. And Anna is an expectation to him. He expects her to be powerful, and he is amused with her abilities. That is why throught the whole fight, he is invoking her, telling her to "show her true power" and this is what he means. But when he hears that Anna is calling for Yoh's help he realizes that Anna is losing, that she can't match up to him, she is under his expectation. For this reason, when he gets kicked *you know where* in 249, he gets up and says "I don't want to hurt you Anna" right. Now I think this has 2 meanings: ONE being that He doesn't want to hurt her because he cares about her, but also another, meaning that he doesn't WANT to hurt her, so she should show her "true self". He thinks that she is hiding her abilities. Perhaps he realizes all the things that Anna is hiding? This is the reason why when Yoh comes, he states that Anna is "simply Anna". She is just Anna, she isn't the high expectations that Hao thinks of her, and neither is she was Hao is reminded of when he looks at her: His mother. He puts Anna on a pedastool, and this is why he cares about her such. He couldn't kill her. She is part of his weakness.
Hao's weakness is the family. He cannot kill the parent-child relationship. May it be guilt, he knows how it feels to lose a parent etc. This is the reason why when Manta's dad comes, he doesn't kill him. Manta's dad is a bastard, but he STILL doesn't kill him after all he did. And moreover, he is human. I don't think it was that he COULDN'T do it, but when he sees something so straightforward with the parent-child relationship he cannot find himself to end it. For this reason I believe that ...
BAH Im tired of TYping. Ill post this right now so you guys can comment-- But Ill post a "Part II" of this post later ^_^. Please don't Spam. Or else Ill contact the mod and tell them to split posts >_<...