Guys, we may come to the realization that Serena would likely remain for Alola. But don't lose heart, we also might have Dawn joining up with him!
I believe that with the Sun and Moon series, the producers are really going to shake things up. It was suspicious in the manner how Ash replied to Serena's remark about Piplup. He said that he knows a specific Pochama who can get carried away. But that also could mean that Serena is likely to come in contact with Dawn and notice how her Piplup is really something else. Dawn and Serena are two of the most popular Pokegirls in the anime. In BW Satoshi tells Hikari that he'll see her again. He certainly was not happy when Dawn left for Johto.
At this rate, we could have had previews of the next series by now.
But something is fishy. They're hiding something, they don't want to reveal anything right now. We would have definite proof of who Ash's companions are by now. The Mallow leak might not count.
There is a chance for Dawn and Piplup to return, but we are also just as likely to have Serena remain as part of the main cast.
Hikari is the light of the sun, the Dawn. Her other names relate to the Sun in some fashion. Her origins are the same as that of Ash, the Pokémon world version of Japan, her name based on the sun, light, relating to solar deities.
Serena can be pronounced as Selena, as セレナ can be either pronounced as Serena or Selena. Japanese don't distinguish between r's and l's. The name which is derived from the name of Greek goddess of the moon, Selene.
This could be the series where we have two major female game-based protagonists traveling with Ash. Ash, Dawn AND Serena? Certainly you guys may think this is impossible. But they fit the Sun and Moon motifs albeit a bit loosely. But this is speculation and the sun and moon anime could blow everyone away.
It could all come together. Ash has nothing to do with either the Sun or the Moon but Dawn and Serena have names relating to them.
There is a reason why Ash lost the league. It was to prepare for the Sun and the Moon. The producers expected a huge backlash and it did happen. How else would they soothe angry fans' concerns?
I mean Pikachu even has a special name for Serena, Pipika. Hikari in pika-speak would be Pikaka. And of course he would say Satoshi as Pikapi.
Dawn = Sun, Solgaleo, Amaterasu, Mithra/Hvare-Khshaeta
Serena = Moon, Lunala, Selene, Ahura Berezant
Ash = Sun+Moon (Eclipse), Satoshi (wisdom as in occult wisdom and Mazda within Ahura Mazda) Marshadow, Ahura Mazda itself?
It is again very likely that Serena will remain with Ash because of the song Candy Girl. She wants to do things her own way, not taking the offer from Yashio. She also wants to travel with him by his side. But to balance things out and the fact that Ash has nothing to do with either the sun or the moon, Serena's lunar presence is balanced out with Dawn's solar presence. And Satoshi is the wisdom, the eclipse the balance that binds all three together for Sun and Moon.
Serena is also an opposite to Dawn in other ways. Dawn wanted to follow in her mother's footsteps and surpass her. Serena did not want to follow in her mother's footsteps and wanted to find something else to do. She may be a Performer but is likely not to tolerate a strict regimen like she had under her mother.
Yeah hard or unusual for me to argue a case for Serena, but she fits somewhere within the grand scheme of things.
Serena and Dawn also behave differently in relation to Ash. Serena has yandere tendencies while Dawn has tsundere tendencies. However, Dawn's tsuntsun behavior is triggered whenever Ash is involved at certain times. She only acts this way towards Ash or someone else when Ash is within earshot. Serena on the other hand is obsessive towards Ash and even Ash noticed her anger when he agreed to dance with Millefeuille. She normally isn't angry towards anyone, not even Ash. But her anger is different than that of Dawn's anger in relation to Ash.
As for Ash, he is Marshadow, the Scorpion/Dolphin of occult wisdom based within the sign of Scorpio. He binds Sun and Moon together in a lunar or solar eclipse.
So in thinking like this, the Moon represents inner peace, mental harmony, in other words serenity. But also the tides of the ocean, water. The Sun represents the radiant light, shining light, that relates to Dawn's name, Hikari, light, burning bright with fire.
But it is also more of a complex set of relations, ties and overlapping theories. Thus they don't fit in neatly in parallels.
And the interactions between the two and Ash are distinct, since Serena is more lunar and Dawn is more solar. Serena is from Kalos, a western region with a lunar goddess Selene. Hikari is from Sinnoh, a Japanese region that retains its solar goddess Amaterasu.
Also another thing to note. Dawn and Serena may be opposites but also consider the fact that shippers do not define the characters in the ships! Dawn may support Amourshipping but because Dawn and Serena could be traveling together, Serena is just as likely to see Pearlshipping. In all honesty all three of them see each other as eventual best of friends. Maybe they feel some jealousy from time to time but you never know. Dawn is basically a female Ash and Serena could also end up admiring Dawn and become an equal of both of them. So if their story were to end, they'd keep it open ended that all three, Ash, Dawn and Serena are on a journey together.