Regina kissing Henry to break this dark curse was lovely, but it didn’t make sense to me why it worked. In S1, Emma broke the curse because (1) Rumple had made her the savior when he added a “safety valve” to the dark curse and (2) Emma believed in her own ability to save everyone. Rumple said it had to be Emma, because she was the product of the true love which had been added to the curse. It couldn’t be Regina the first time around.
With this re-created dark curse, which was just a rehash of the first one, Emma still should have been the savior, since the drop of true love potion had originally come from her parents. In fact, it was Emma’s parents who cast this particular curse this time. So why was Regina suddenly the savior this time around? As far as we know, Regina didn’t add a safety valve to make herself the savior. So why now? What was it about this particular casting of the curse that made her break it? I know that Regina has true love for Henry, but that love should have been added to the parchment on which the curse was written as a safety valve, thereby ensuring Regina could break it.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy