Yup. Since the kings, who are descendants of the dragon, are destined to obsess over the Regas because of the dragon’s power inside them (which is bound by the dragon’s promise to have a Regas), naturally someone taking that power into their body comes with all the power’s traits - including the negative ones.
Such stupidity. So this is why our mc was a burly Regas (mountain person), and then an attractive blond. Seems like everyone’s reincarnated huh? Guessing the king chose a burly mountain Regas back then too. Then I guess that burly mountain man died and got reincarnated into a blond council member- by whatever means. Then died again - causing the king to wither away in depression. (Then the king was eaten)
It’s more like the mountain regas have been the most successful with producing regas that multiple generations of their kings have liked. Just based on yan’s ancestor saying something along the lines of “We finally got our regas chosen and not whoever from the mountains after trying for so long”
It’s just a coincidence now that one of the regas chosen by the king this time was from either truyde’s or yan’s faction or someone from the council and not anyone from the mountains (maybe thats why that regas passed away too quick?) and like the parasites the council are, they dug their claws into this chance and fully shunned the mountain regas and planting their blonde regas next to their king and idk how they managed to get these kings to fall inlove with their blonde regas, but either way, truyde and yan were successful in essentially taking over control of the kingdom starting from here.
So I was basing my comment off the fact that the current main characters and the past characters look nearly the same- enough for the MC to recognize them at a glance, and even mistake one for Trude initially.
Also, it’s possible that the black potion is made from the corpse of each king’s Regas. That could be related to why they keep finding the real one and then killing them- instead of simply blocking whichever new real Regas from having access to the king.
Also, because they said, “we worked so hard to get a Regas from the council instead of those mountain men” -BUT, how does one “work hard” at making something that’s predetermined? After all, Abel was the true Regas, even before he met the prince (at the beginning of the story). It’s something decided by the dragon blood/fate, not by the king’s own choice.
So it really doesn’t make sense for them to “work hard” to MAKE a Regus, unless they were planning to replace a Regas from the beginning.

He was so messed up,now we know why he falls for regas