
Are you confused about the politics? If so:
The powerful nobles families decided to take over the kingdom by controlling the dragon royals. Now that they have pretty much achieved their goal through the use of a poison, Duke Truyde (the blond one) is also getting rid of his allies. He is the main antagonist, and the MC and the others are trying to figure out what his family's weakness is. Apparently it has to do with something that happened long ago, but only a real Regas (aka our MC) can know learn what that weakness is (cause magic).
Additionally, all the noble families that sought to control the royal dragon bloodline are cursed. The white haired marquis' family (the family who "knows" what the Truyde family weakness is) is cursed as any Regas they have will fall in love with the king (and they need a Regas to make use of the information they have). The Truyde family is cursed to fall in love with the king's Regas (in this case, Abel as he is in his new body). I am not sure what Duke Duncan's (the dude with shoulder-length brown hair) family's curse is.
If there's any particular questions you have, you can ask them. Even if I don't know the answer, I'm sure someone else will know

I might be misremembering but I think that when he was little, an still being watched by the nobles, he drank some of it. But rn he's not taking any poison. His plan so far has been to be away at war to avoid coming back to the palace. He knows that once he comes back to the palace, they'll try to poison everything around him. Duke Truyde controls the entire palace so the ML won't be safe. The ML has been trying to get power while he has been away so that he can return and kill all his enemies. We shall see how that goes.

To be clear, the ML has been out at war since he was a child (after Abel died) which fucked up the nobles' plan. They originally wanted the ML start consuming poison since young so that he would grow up to be a fool. But because he went off to war (which I think was something the king helped him do), and because Abel protected him as a kid, he was able to avoid the plan the nobles had and gain autonomy.

Fair and I wonder the same. I think that's what Karas ends up doing in Abel's prophetic dream along with destroying the entire country. I think Abel's goal has always been to push him towards a more civilized approach where he doesn't immediately resort to killing. Perhaps what Abel taught him when young stuck with him, and maybe that's why he hasn't just gone and kill everyone.
Guyssss im confused LOL, the last couple of chapters have thrown me into a loop. Could someone explain to me pls