Regret—that one thing sentient beings were supposed to rely on to learn from their mistakes and grow from their failures. As far as Huan Yi was concerned, regret was only as useful as one's ability to fix what caused it in the first place, or at least make sure that such events would never happen again.
With that definition in mind, Huan Yi's regrets became the driving force of flawless domination. But Ailong's...had absolutely no value. And if there was one thing that the Primordial Evil despised more than traitors, it was remorseful traitors.
"Insufferable...oh so insufferable. After facing the consequences of your betrayal, you cry and beg for forgiveness—swearing that if you could go back to the past, you would never commit those mistakes again. But of course, you wouldn't. I've already shown you the consequences.
So unless you got addicted to pain and suffering, why would you repeat the mistakes that led to your punishment?