Just once

In the introduction and end of the novel, the author's explanation has been very sufficient. But many people only look at translated novels, and do not pay attention to the introduction/ explanation of other places.
This is not a story in the manga, she created this new story to show the inner entanglement of the characters. And this new story is adapted from manga. And her original intention is not to let Fei and Yoh complete the sexual relationships, but she compromised. Do you know why she must explain? Because this part of the modification is somehow confusing the reader. She had to make a reasonable explanation beforehand, and she just wanted to prove that she didn't deliberately confuse the reader.
She's just creating a parallel world with empathy. You can try to think about the prototype of the story.You'll find it's really interesting.

?????????

"But these are things that Feilon didn't know."

What Fei didn't know: he doesn't know that Yoh intends to return to his side as his equal. How he's going to pull that off, I don't know. "Yoh in power" would be interesting. Who knows? Maybe he'll be the one to save the day in this current arc.

"Feilon didn't know why Yoh betrayed him"

Fei's not stupid. He realized fairly quickly that Yoh had been Asami's man all along. This was even talked about in FnR.

"so why does he suggest Asami steal Fei's deed?"

Yoh was working for Asami and despite his feelings for Fei, he was still loyal to Asami. Yoh could've just arranged for Akihito to "escape" and just delivered to Asami in the first place, but he apparently was beginning to struggle with that loyalty. After Akihito's first attempted escape, he was more closely watched so Yoh needed to come up with another solution. Stealing the deed gave Asami leverage in securing Akihito's safe return. In the end, Yoh remained staunchly loyal to Asami; he risked his life, destroyed his relationship with Fei and the Bai She, and even accepted that Asami might kill Fei... all to return Akihito to Asami.

Btw, YA provides an outline for the novelists. The inner dialogue of the characters is in their voice, not YA's. I'm not sure how much input YA has after its written, but I'm going to guess "not much" since there are a few glaring inconsistencies in which background information in FnR does not match up with what is presented in the manga. Then again, novelizations (or the inverse of book-to-screen) often create AUs.

I agree with you on many things except on two:
1- Asami would kill Feilong
2 - Yoh accepted Fei's death

Akihito stands between Asami and Fei but I am convinced that Asami would not come to kill Feilong because I believe Aki's conviction that the two men did not want to die or kill was the truth as communicated by YA.
2- I think Yoh just did not arrive in time to prevent the clash as Asami failed to prevent Yuri from shooting. Yoh tries to find a solution that can save Akihito and Feilong. A diplomatic solution. Asami could have killed Fei before.

Asami and Fei are two sides of the same medal. Same goals, same darkness, enemies, demanding parents. They even shared Akihito (physically, not sentimental). Asami should have killed Feilong for having kidnapped Aki. I believe that Asami and Fei are bound by something strong that is not love or passion. Something Asami knows and Fei does not know. I suppose, a bond between their parents (Toh and Asami's father?), Or a kinship relationship. I have this feeling. They are not just companions of weapons.

I always think of a phrase I've never been able to interpret: "It's neither love nor passion, then what is it burning in my heart?" Who feels this phrase: Feilong? Asami?
(vol.2 ch 5 page 2)

Yoh asked for forgiveness when he gave Fei the gun, Feilong forgave him by not taking his life.

It does not have to be by blood of kinship. That Toh situation was pretty intense. that could have bound them in a kind of band of brothers way? Having to kill your own father to save your own life. One of them having to shoot Toh, blood spilled like that can build a kind of bond on it's own.

this is not just this. Asami is too indulgent with Feilong. The situation with Toh was intense but only for Asami. I mean that Asami killed his ally after all (Toh), Feilong does not see Toh as his father, he does not live Toh's death as a problem: his tragedy has already been consumed with the death of old Liu

the relationship between Asami and Feilong is enclosed in the answer to this question. But I do not know the answer. What is a strong feeling enough to burn in the heart, without being love or passion? Hate? Vengeance? Certainly not friendship. I do not know. it is an ambiguous question for anyone who pronounces it. (I think Asami, but it is not discounted)

I didn't say Asami would kill Fei Long. I only mentioned that in Asami's discussion with Yoh, he'd threatened to get revenge on Fei for what he'd done, no matter how things turned out. Yoh had no way of knowing whether or not Asami would actually kill him if pressed, but yet he still carried on with his duties.

There's no question that neither Asami or Fei wanted to kill the other. That was a key point in their contentious relationship. I still think Fei looked like he was ready to die at Asami's hand on the ship (much like Yoh was ready to die at Fei's hand).

Yes, the trading of the deed for Akihito's life was the best possible solution. However, once things went south, Yoh's first priority was Akihito's life, not Fei Long's. I dunno... maybe he assumed that Fei would be well protected by the Bai She (haha... fail.)

Now that I understand your thinking better, I think I agree with you completely

if yoh had simply delivered Akihito to Asami, Feilong's reputation would be compromised, and Fei would have weakened too much in Baishe. The compromise makes time and allows Fei to have an excuse to give Akihito to Asami without losing his face. I think Yoh has tried to protect Feilong in his own way. I remember that Yoh's position is very risky: Asami understands that Yoh is timid because there is a link with Fei, he asks him: "Are you sure you do not want to stay with Feilong?" Seven years are a long time ... "Asami understood all. But he accepts why he does not want to come to an extreme confrontation with Feilong. Yoh also runs risks with Asami. Do not forget it. Asami threatens him: "If takaba does not come back, your seven years at my service have been useless." Dangerous.

I conclude by saying that in my opinion, perspective is to be overturned. Yoh loves Feilong and chooses to save Akihito as the last mission to Asami. But he knows that true betrayal has been done against Asami. We recall that Yoh has been working for Asami for ever. He is a Japanese man. He should only give Akihito to Asami. Ever thought of Feilong's security (in theory his "work") is already a betrayal.

Honestly, Yoh's logic made no sense to me. By forcing Fei Long to trade Akihito for the deed, Yoh weakened Fei's position even more, prompting one of the Bai She to suggest a takeover once the trade for Akihito was complete.

I never thought to interpret Asami's statement "seven years you've spent will all been in vain (if Takaba doesn't make it back safely)" as a threat toward Yoh. I think he meant the seven years of Yoh working with Fei Long would've been wasted.* If anything, that seems like a vague threat toward Fei. But I can see how you could read it the other way.

*My evidence comes from Yoh's statement beforehand when Asami asks why he didn't report what Fei had been planning earlier, and Yoh stammers "I.. I know, but I never expected Fei Long to go this far..." THEN he walks it back, "...but this is not a matter involving the organization; it's a personal matter between you and Fei Long over which I have no..." (Asami cuts him off before he can say more).

I think it's as if Asami wanted to say "be careful, the seven years you have dedicated to me and of whom I am satisfied, they do not count anything for me if something happens to Akihito ... who is the most important thing now" ; something like "I trust you ... but do not mistake on Aki ...

You are all talking about your understanding, and the important thing is the original, not the result of your understanding.

And what if she were right?

Feilong , when Asami came to Hong Kong, sent assassins to greet him. They fought when they met. Felong bro. takes it out on Fei , who leaves the house and winds up with Asami.( they have already had a few fights they fought together.) Asami tells him Toh wants him , They meet Toh Fei says no. Fei tells Asami he has routes of his own that his family does not know abt. setting up a deal Asami tells Fei he is a man who will go his own way he wont go with Toh. that are attacked again by Fei's bro. they have not even gotten to the end yet.

It is clearly not saying that I'm right. It is my interpretation, my vision of events, which could be completely wrong. But I find it useful and enjoyable to compare my feelings with that of other readers and to know different points of view