
The story kind of expect you to have background knowledge of heavenly contribution already. Its a bit like how isekai stories kind of expect you to know the term isekai already I guess.
In general, Ao Ao is the second son of the dragon king. For some reason, ever since he is born, his power is pretty much non-existing. In this story, the dragons have a ball that held their power (its internal i think), but Aoao was born without one. In this story, Dragons, before they reach adulthood will have to go through heavenly contribution. Thats basically a trial where the heavens sends thunder down at the being, and they have to take it. If they survive, they gain power, if they didnt, they die. With AoAo's original power There is no way that he will survive. So he went to the human world to search for a dragon ball to rise his power. Thats basically the background.
AoAo's power is so weak that he could not hold an Human teenage form without help. Thats where that TuDi gave him his power to help him. When his trial came, Ao Ao never found the ball (not sure if it even exist) so he is still weak. AoAo'a brother and Ryan took the thunder for him which injure them. Ryan seems to have recovered, he only took 1, while Aoao's brother took most of it and is much worst off and is currently recover at the doctor's place.
From the story so far, Ryan is an western dragon. They have meet when they were younger and spend some time together, during which Ryan have fell in love with AoAo. It might or might not have been a mutual thing, but AoAo definitely cared about Ryan in the past. It seems that Ryan might have dual personality, perhaps his more primal dragon side? But for some reason he has probably sexually assaulted AoAo before, as we can see from AoAo's random flash backs.
This part im not actually 100% confident about, but here goes. Something also happened to AoAo in the past (not sure if same raping event), but AoAo got seriously injured and basically got reborn in a sense. This insistent must be at least partially cause by Ryan since AoAo's brother knows about it, and it's why he hates Ryan. The brother might have assist in AoAo's rebirth (my guess is that AoAo was so injured that that is the only way to save him). It's either that or AoAo did something tababo because of Ryan, and the punishment was have him be reborn.
They have a part in the comic of when AoAo is born, and the Brother actually named him and he said that he will protect him this time (as he failed to protect AoAo the first time). The forced rebirth is probably the reason why AoAo's power is sealed (? Or why he is born damaged). I think the story kind of suggest the brother might have something to do with AoAo's lost memory but might be remembering that part wrong. This is why even though Ryan's scale is AoAo's, its larger than AoAo's current scale. So without knowing anything AoAo came to the human world, and met Ryan again and some of his memory pieces came back here and there. Ryan has all his memory though, so he remembers everything. He didnt know about AoAo's rebirth though, and have no idea why AoAo is in the state he is.
I think the Tudi and AoAo's brother side is pretty straight forward compare AoAo's story which has too many random flash backs and you have to work hard to fill in the story yourself. Its in the recent chapters we found out why Tudi wants to kill AoAo's brother so much that he is using AoAo just to get a chance at him. The brother is kind of a jackass who, didnt even know it, damaged Tudi when Tudi is on his way to completing his cultivation and ascending to heaven. In This type of Chinese novel setting, usually, animals and plants can become gods through cultivation. Dragons are kind of born as gods, but rather than living in heaven they live And rule the ocean. This ruin Tudi's ability to ascend to heaven, so he set out on a journey to get his revenge. many attempted to kill the brother ended in failure. The last one got him caught by the brother. At that point, he looks like a pretty boy, so the brother end up raping him, and further damaging Tudi's internal cultivation. After that Tudi escaped from the brother somehow, and end up hiding on land. Many many Years later he somehow got in touch with AoAo, and decide to try killing the brother again after knowing that the brother will definitely help AoAo take the thunder trial. It seems that the brother's memory might have also gotten somewhat blocked since he doesnt seem to remember Tudi at all when they met again (hundreds of year might have pasted so maybe he just forgot haha...). But yeah, thats' their story.
Hope this helps. This story is supposed to be comedy so they kinda just slip their story in here and there and let it drag out... which makes it hard to piece together... (づ ̄ ³ ̄)づ

no problem ouo. the story so far hasnt quite reveal what that other personality Ryan is suppressing is I think. It might be his more primal dragon side, like instinct, which is a not too uncommon theme for non human. That would explain how he would rape AoAo when he treasured him so much even back then. just a theory though, Only time will tell.
Am I the only one who don't understand plot at all, but still reading?