Oh you know, actually, watching the entire episode without skimming, I LOVE the ending.
The ending dialogue concluded everything quite well. When flashbacks of Dan's pervious lifetime made Dan realize what a jerk he was to have made a promise without being sincere, he decided to make a sacrifice, a change for once. As Nirad, the present lifetime, he loves Rissa but in the pervious lifetime as Khon Rad, seems like Dan loved both Pikoon and Salapee. Although, people are reincarnated, their lifetimes only contain memories but Nirad isn't Khon Rad. That's why Dan said I love you to Rissa for one last time as Nirad. And then said to Ae, I am Nirad but from this moment onwards, I will be your Khon Rad forever. As Khon Rad, Nirad realized that he did love Pikoon thus willing to die with her, not only to repay for the sins/crimes he committed against her through guilt but also because he did love her. Ae asked why, was he afraid of seeing her every lifetime and Dan answered, I'm not afraid but I'm afraid for you as we weren't created for one another so every lifetime, you will be in pain that's why there will be no next lifetimes, we will be like this forever. Meaning, yes, even though Dan and Ploy are meant to be soulmates, but Dan has chosen to remain as ghosts like this for an eternity so he and Ae will be together and never have to depart again for an eternity. Isn't that just sweet? So yes, all of those tears, Khon Rad did return to Pikoon's side and loves her. They will be together forever.
So Khon Rad and Pikoon worked around fate. I totally love the ending scene. And when Dan hugged Ae towards the very end, finally, he was sincere.
Does that make sense? Because if Dan didn't love Ae at all, he would be an unhappy ghost but at the ending scene, both were full of happiness together! So in conclusion, Dan loves Ae even if they weren't soulmates but if you think about it, it was fate for them to meet, fall in love, and end up together. ^_^