CGPT

Honestly I completely understand where he's coming from. We have forgotten because there's been a lot of happy hungry bunch in the middle, but you need to remember that the happiness the dragons have now with Yona is an anomaly. For centuries, the dragons' lives was hell on earth. Removing from the equation the fact that every generation after the first one has died before reaching 30, White Dragon was enshrined and cloistered by his tribe and was unable to leave their lands for any reason, everything was decided for them, their food, their clothing, their partners, free will was all but nonexistent. Blue Dragon was imprisoned underground and ostracized to the point that the previous holder cried in gratitude at his powers finally disappearing for good. Green Dragon lived chained to the wall so that he couldn't escape their daily abuse.
And Zeno kept seeing all of this happen, for centuries. And even if he had taken them and saved them, it would be meaningless, because they would die before 30 and the next generation would be born again back in the tribe, to be subject to the same fate. Now, after all that time, the four dragons are finally free and happy again, but Zeno knows that that will be only until the day Yona dies. There's no guarantee her children will be able to connect with the dragons. When she's gone, it will be the same circle back again. Yona didn't reform or destroy their villages, the same traditions remain, and the dragons will be treated the same way. As monsters. and who knows if another Hiryuu reincarnation will come about ever, he'll probably not.
Honestly Zeno is doing exactly what I expected of him. After centuries of suffering, a couple years of happiness is as ephemeral as a glass of water after wandering the desert for months. Would you rather take a couple more glasses of water, or just leave the desert altogether? Its a very logical move on his part and very in line with his character. He wants the suffering to end, for all of them.

That’s good and all, but this is the 3 Dragons’ FIRST LIFE. Are you really saying that they should just die like this despite it being against their will? They can’t even live it to the fullest?
I know the past dragons suffered but can’t the 3 current dragons just finally find some purpose and happiness in their lives now? Just taking it like this seems like a dick move, even for Zeno.

Zeno can die. I believe he truly deserves to rest but the other 3 should be able to live as them

It makes me wonder, if the dragons died naturally wouldn’t that make new dragons again and the new ones would have the suffer like the older generations?
I believe Zeno wants to stop his immorality, stop the dragon curse, and secretly doesn’t want to see current dragons death bc he grew so close to them which was different than the previous generations.
I don’t know anymore bc I’m pretty conflicted about this.
Zeno is my favourite dragon and I love the happy hungry bunch and I those days living in the forest, every updated chapter is freaking torture to read （/TДT)/

I am saying that the actions make sense for Zeno's character, not that they are fair. FWIW, we've already been getting hints that Jaeha's powers were degenerating and he's 27, so apparently, being close to Yona is not going to help their curse, but rather it seems to have somehow exacerbated it since they are using their powers more often. Also, we need to remember that unlike the other guys, Zeno is the actual original dragon that took human form to accompany Hiryuu on earth. He's never been human. He learned how to be human with his wife, and then he saw her slowly die and turn to dust in his arms. And then when his wife died and he went in search of the descendants of the dragons who were the last people he could relate to, he found they were treated like crap by the very humans Hiryuu had wanted to protect. I'm sorry, but him being unwilling to risk everything breaking apart a second time is 100% understandable, even if we do not like it. In his mind, the dragons have at most 5 or 6 more years of happiness before the cycle repeats itself (probably much less than that in Jaeha's case), and considering that he is also clearly degenerating, he might be thinking that this might be the last chance he has to break this vicious circle, and sacrificing 5 years of happiness vs saving centuries of suffering sounds like an easy tradeoff on his mind.

I get what you're saying but 1)he should just kill the future dragons then, I'd rather a kid who doesn't know anything die than a fully formed person who does good and is good trying to live their life to the fullest after decades of abuse and 2) Zeno isn't the dragon incarnate. He drank the dragons BLOOD so he is a "dragon", but not the ACTUAL dragon ykwim