The premise is not bad, BUT it's all over the place and character relationships make no sense.
First, MC is given a second chance to make amends (?) for his tribe. But the differences between the past and the present is not even made clear, so it's ultra confusing as to what exactly is going on and what his goals are. The relationship with ML is also super "huh?" as it seems like MC gets jealous of other men getting too chummy with ML, but there hasn't been proper explanation as to why, or when MC likes ML. In fact, it's not even clear whether MC likes ML, which makes it even more puzzling as to why he's jealous or upset or whatever.
And just like the usual poorly written BLs, there's a random gay second couple (?) that pops out, and doesn't really add much value to the story.
To summarise, this whole story is so poorly executed that we have no idea what exactly is going on. We know vaguely what is happening, but the story is not even fleshed out that makes me care about the plot nor the characters. I think only the MC (Bai Ye) is decently executed, the others are just wtf. What's even worse is the relationships each character has with each other. Why is MC acting so jealous-ish and mopey? Isn't he some great demon or whatever? I know he can be a great demon and a jealous person at the same time, but it just makes him seem utterly useless that he gets affected by every single thing the ML says. I just wish the MC's personality was better characterised (not some guy who goes mildly jealous and pissy at every single thing) and the relationships between the characters better fleshed out. We aren't even able to see the extent of their feelings for each other because it's not even properly introduced!
Lastly, the thing about romance stories that I absolutely loathe, are the sudden switch in priorities, where every other person or thing is worthless in the face of L-O-V-E. What I mean is how even though the protagonist (or any character for that matter) has responsibilities, has friends, has family, it all becomes insignificant when they meet their love interest. In this case, his whole revenge, his position as the king, and his indebtedness to his friend is all diluted and made stupid. It's as if his whole existence is just revolving around the ML and the rest is not important. Completely unrealistic and dumb.
TLDR; Confusing as heck, characters, plot and relationships are badly written