The only real details we were given were
1) trying to force a marriage with Helios to gain imperial power
2) slave trading
3) embezzlement
4) murder of innocents within their territory (I think, part of that came from Diana so who knows)
5) high enough taxes to impact the people badly (again according to Diana with her whole greed tirade)
6) and what the book focused on. Bullying Diana in high society like a typical villainess you see in tons of other stories.
The only two points that were made a big deal out of though were number 1 and 6. The other details came later, but if I'm remembering right points 2 and 3 came from cail (I think that's how its spelled, idk I'm tired) to add additional justification to Helios for his choice to go poison them to death. Anyway that's all I can think of right now. Like I said the story framed their poisoning as being solely motivated my points 1 and 6, but did briefly add details showing that they were the worst of the worst. Much of the original story seems to have mostly been Diane's pov, and tbh I doubt that hypocrite has/had the brainpower to understand the whole picture beyond "waaa waaa I'm being bullied!" and "waa waa Helios might be stolen from me!". But the last bit is just my personal opinion. Anyway I've talked long enough, I hope this helps in some way if I've got all my facts straight.
What did the duke and duchess Orcus and their daughter letona do again to get food poisoned?