My opinion about ash & koi, they're my fav

Ashley is the perfect example of a great husband but a terrible father. Koi wasn't a good father either, and one of their issues for me was that they always prioritized their marriage over their children.

Ashley originally only wanted one child, while Koi wanted a big family, they eventually ended up with six children, even though Koi had wanted twelve, which is honestly missed up and crazy considering they already can't properly raise and care for the children they had.

Imo, Ashley deserves hate the most, he was abusive, controlling, and often let his possessiveness over Koi affect the way he treated his children, but koi also failed as parent because he rarely stepped in to protect the children from Ashley

Even tho i agree Ashley had one of the most tragic backstories in the series, this doesn't justify anything from his actions.

Bliss, who was a dominant omega like Koi, was clearly Ashley's fav. Ashley showed him far more love and warmth than he did many of the older children, Nathaniel became someone Ashley viewed as a rival/competition for Koi's attention. His jealousy over that with Koi led Nathaniel to distance himself from koi to avoid Ashley's possessiveness.
(I don't remember this part the best)

Grayson was treated especially horribly after the poisoning incident. Even though he was only 9 years old, Ashley punishment to him was choking him and locking him in the basement.

Also, seeing Chase crying because Ashley wouldn't let him see Koi was so sad, and it's understandable why Chase grew distant from his parents later.

Idk if i wanted to mention this too, but there were pheromone parties that they send the children to, so they can understand their society and environment better and pheromones interactions

Overall, imo the poisoning incident didn't make Ashley a bad father; because he always was a one, it just made everything worse.