Well, in addition to the more well - known female characters like Misty, Dawn, and Serena, there could be new original characters created by the fanfic author. These new characters could be designed specifically to be part of Ash's 'ladies man' story. Maybe a mysterious female trainer from a far - off region who hears about Ash and comes to meet him. Also, Nurse Joy from different regions could potentially play a role, as they are often kind and helpful towards Ash in the original, and this could be developed further in the fanfic.
One cool thing about 'pokemon ash ladies man fanfic' could be the different storylines that can emerge from this concept. For example, it might explore how Ash's newfound status as a ladies man affects his journey to become a Pokemon master. Does it create distractions? Or does it help him in some unexpected ways? The fanfic could also play with the idea of how the other male characters react to Ash's popularity among the ladies.
Misty would also be there to help. She's tough and resourceful. She might use her water - type Pokemon to cool down any burns if Ash has them, or to create a barricade against any approaching danger. Professor Oak could also play a role. He has a lot of knowledge and resources. He might send over some special medicine or a flying - type Pokemon to quickly transport Ash to his lab for proper treatment.
Gary Oak is a likely character. He has always been a rival to Ash and in fanfiction, he might betray Ash out of jealousy or a desire to be the ultimate Pokémon trainer. Another could be Misty. Maybe she gets influenced by some external force or her own insecurities and turns against Ash. Brock could also be a candidate in some stories. If he falls in love with a girl who has a vendetta against Ash, he might be forced to choose between his loyalty to Ash and his new love interest.
Obviously Lana herself is the central character. Her Pokemon partners are very likely to be involved. For example, Popplio might be constantly by her side, providing emotional support. Ash and his Pikachu could also be part of the story. Ash, being a good friend, would probably offer his help and advice. Misty might also be there, sharing her own experiences or just being a good friend to Lana during this time. Brock could be involved too, perhaps using his knowledge of Pokemon and nature to ensure Lana has a healthy pregnancy. And other trainers from the Pokemon world who are friends with Lana might make appearances to show their support and be part of the story.
Obviously, Ash would be the main character since he's the one collapsing. His Pikachu would most likely be a key character as well. Pikachu is always by Ash's side and would probably be very concerned and try to help when Ash collapses.
He'll surely meet the Alola region's professors. Also, the local trial captains are very likely to cross paths with Ash. And of course, the regular Pokémon trainers in Alola.
Gary could be a likely character. He has always been Ash's rival and there could be a plot where his jealousy or some other motive leads him to betray Ash. Another could be one of his so - called friends from the Pokemon League who might be influenced by power or some dark secret. Or, in some really dark fanfictions, it could be a Pokemon that Ash trusted deeply but for some reason turns on him.
Also, any friends that Renesmee has made throughout her life could be involved. They might be there to offer moral support, or there could be some who are jealous or envious of her situation, which could add some drama to the fanfic.
The main characters would surely include Ash. In Pokemon Red, the rival character, Gary (or whatever name you choose for the rival in the game), could also play a major role. And of course, the various gym leaders from Pokemon Red. They could have different encounters with Ash, some might be friendly and help him, while others could be more challenging opponents. Also, Professor Oak might be involved, as he is connected to both Ash's world and the world of Pokemon Red in some ways.
The main character is surely Ash. He is the one who is being betrayed. Mew is another important one. It might be that Mew is the cause, directly or indirectly, of Ash's betrayal. Then, Ash's Pokémon partners are likely to be main characters too. They might be confused or forced to side against Ash. And there could be some antagonists in the story, perhaps some evil trainers or organizations who are behind the plot to make Ash look bad and get betrayed.