"Folklore has it that on moonless nights, this Pokémon will make people see horrific nightmares." As many of you know, Ash lost the Sinnoh League to Tobias, a trainer who owns a Darkrai. Since Ash was the first person to actually defeat his Darkrai in battle, Tobias sought out a way to discourage Ash in the future. The night after the League ended, Tobias sent out his Darkrai to lock both Ash and Pikachu within a nightmare. This nightmare involved Ash and Pikachu heading to Unova to win the league there, however, Ash appears to be inexperienced and his companions were constantly putting Ash down for being different. In the real world, Brock takes both Ash and Pikachu to Pallet Town believing both of them are in a coma. Delia looks after the two of them and gets several visits from Dawn and Cynthia, hence the reason they appear in the meloetta portion of Ash's nightmare. Some time later, Alexa arrives in Pallet Town to write a document about the effects of the nightmares caused by Darkrai. Alexa gives Ash and Pikachu a lunar wing from when she was documenting Cresselia and the two of them wake up from their long slumber. Alexa then convinces Ash that if he wants to continue his dream of becoming a pokemon master, she would recommend for them to go to Kalos next. Best Wishes never actually happened, and XY is the direct sequel to Diamond and Pearl.