There actually is a reason. Tell me if you want me to spoil it.
Please tell mee
SPOILER
Apparently there's a really important document which disappeared (one that could decide the end of the war) and the father was the only one who could have gotten it, so the emperor wants to keep him close in order to take it back. The father himself doesn't seem to know about it.
What kind of document?
I don't remember exactly but I think it was something about the location of dragon's veins between Dashun and Quianzhu, Quianzhu shot the bird who was holding the document and it fell right on Feng jin huan. (from what I understood, I kinda skipped this part)
Ohhh. Interesting, thanks!
It is called "dragon vein" or something. If I'm not wrong it will appear later in the next arc after the 3rd prince executed.
Now that's a worthwhile spoiler, thanks!
ლ(´ڡ`ლ)
Ohhh
but the execution of the 3rd prince is still far away, in the novel the map is spoken after a few hundred chapters.
Yuheng won't kill him in the next few chapters, after challenging him to a fight to the death?
No, seventh brother stops her when he is almost dead, it only leaves him crippled. It is the king who sends him to behead because he tries to usurp the throne with the 4th prince.
Aww too bad
I've loved this story since the beginning. However, the Feng family sure is fucked up to the bone, how did they manage to not lower their rank until now? XD