Diana is both so insensitive and selfish
Back then during the "ending" of the story when she finally married Helios, she didn't even care nor mind that Kael almost killed himself in his self-despair both losing his past love and best friend
She forgot/doesn't even know that what he did only bought him pain, and now didn't understand that Kael would only go through that pain again coz it led him to Hess
Diana takes the crown in being super delusional
Diana is sole competitor of that crown at this point lmao
But in my opinion I don't think he meant it that way, he was talking about people having different view on what is right and wrong, so to me he was saying that even if he knew the outcome he would still do it, not necessarily because all of this led to Hess, but because that's how he is in the end.
He was explaining that to him what he did needed to be done so he'd do it again and this crazy woman really took his words and put some self-absorbed bullshit on it lmao