We know that Chen got his information from Zhu and can assume that Lan Di got his information from Tentei, so were we to make the assumption that Zhu is actually Tentei, the story that Iwao killed Sunming could be traced back to a single source with both a history of lying and a pretty decent motive for lying in this instance. Zhu (a friend of Sunming) being Tentei would also explain why Lan Di may have willingly gone with the Chi You Men upon being told of his father’s deat
This would be cool if the idea is to treat Tentei's reveal as a plot twist rather than a new character. It would also make sense why Lan Di leaves Zhu on the rooftop at the end of S2. However, Chai does say that Lan Di hates Yuanda Zhu in S1 and Zhang seems to be pretty loyal to Zhu so it might be difficult to portray a convincing double life.
This is an interesting thread of ideas but I would have to concur that it doesn't make sense for Zhu to be Tentei or a part of the CYM.
For one, Zhu sends the letter to Iwao warning him about "those who pursue the mirror". Secondly it makes no sense for him to be in hiding, pursued by the CYM, then fake his capture to reveal information to Ryo about the origin of the mirrors. It begs the question, why go through all that trouble? Especially if he already knew that Iwao took both mirrors back to Japan and when Ryo just hands him the Phoenix Mirror he gives it back.
Also, everyone in Zhu's network seems to help Ryo against the CYM.
EDIT: I should add that Lan Di going with CYM doesn't really need further explanation. It seems from the Ziming flashback that their M.O. is recruiting young men who feel abandoned and exploiting their need for revenge (not unlike a lot of extremist groups). I do wish some of this was more explored in the game though.
Yea if Lan Di is going to be portrayed as sympathetic then this is pretty much the only way to go unless Sunming left him literally no choice. I'm hoping for this because Lan Di is a more important character than Iwao or Sunming and he didn't appear to know that Iwao had both mirrors; hopefully that changes the arithmetic in his mind (ie: if Iwao was such a piece of shit, why did he have both keys to a treasure that he didn't collect?).
I'm not convinced Lan Di is going to be sympathetic, especially after Shenmue 3. He may gain more nuance (hopefully), but I can't see him being redeemed in the end. It really seems like he is the villain who is going to be defeated somehow.
Conversely, Iwao being the killer (for whatever reason) could prove important in Ryo’s arc in terms of recognizing the parallels between himself and Lan Di and the whole ‘an eye for an eye leaves the world blind’ fable which could just as easily be where Yu is heading. I suppose this could still work even if Iwao wasn’t the killer as Lan Di believed he was avenging his father, but Iwao not being the squeaky clean man Ryo believed him to have been and Ryo having to come to terms with that may be more interesting from a narrative perspective
I really like this idea. I've toyed with both options in my mind about whether it would be better for Iwao to be innocent or not. I remember reading a long time ago whe S2 came out and I went way down the rabbit hole of Chinese mythology/history that in Chinese lore thunder signifies injustice (can't remember where I read it, it was ages ago). Considering the shot of the dojo after Iwao dies with the lightning and thunder, and the significance of the "day the snow turned to rain" I wonder if this is more than a coincidence. It doesn't answer whether Iwao killed Zhao or not, but could be a clue that Lan Di was unjustified in his "revenge"
I think that's what makes it a compelling mystery. Even more so than the mirrors, it feels pivotal to Shenmue's story because the story is almost Iwao's as much as Ryo's.
Obviously this could easily mean that he knew someone was coming for him, not necessarily Lan Di but it also casts Zhu's letter as suspicious-- surely Iwao knew to beware of those who pursue the mirrors?
I think this is on the money. Iwao knew
someone was coming, maybe even the CYM, but he was surprised at who it was (death wears a familiar face). I think this either means that, as Tomboz pointed out, he thought Lan Di was dead, or more interestingly, that he felt justified in killing Zhao not expecting retribution for it.