Well, they might feel a range of emotions. Some could be angry, feeling that they were wronged after putting their trust in Ash. Others might be heartbroken, especially if they had deeper feelings for him. For example, one of the harem members who was really close to Ash might go into a state of denial at first, not wanting to believe that he could do such a thing.
The emotional turmoil is a big consequence. The girls in the harem might experience heartbreak, anger, and confusion. This can change their personalities and the dynamics of the harem. For example, a once - happy - go - lucky girl might become withdrawn. And if the fanfic has a larger plot outside of just the harem, Ash's betrayal could also affect his ability to achieve other goals, like winning battles or achieving some sort of quest. Because the harem might have been a source of support, both emotionally and in terms of resources, and now that's all disrupted.
It's inappropriate. The Pokémon world is built on values like friendship, growth, and adventure. Fanfics should enhance these aspects rather than introduce improper elements. The 'lemon harem' in the title gives the impression of content that is not in line with the positive and family - oriented nature of Pokémon.
One reason could be power. Maybe he was offered a great deal of power by an outside force in exchange for betraying the harem. Another could be jealousy. If there was someone in the harem who was getting more attention or was more successful than him in some way, he might have been driven by envy to betray them.
Often, in 'pokemon ash and harem fanfic', Ash becomes more confident. With the support of the characters in his harem, he might take on tougher challenges. For example, if a girl in the harem is really good at a certain type of Pokémon battle, Ash could learn from her and become better at that too.
A proper Pokémon fanfic should focus on things like Ash's journey to become a Pokémon master, his battles, and his friendships with his Pokémon and other trainers. 'pokemon ash's lemon harem fanfic' sounds like it might deviate from the positive and clean themes of the original Pokémon series, so it's not something that should be promoted.
A common theme in such fanfictions could be Ash's adventures in Alola while building relationships with different characters. Maybe he forms special bonds with his Pokémon and the people around him in a more romantic or friendship - deepening way.
Often, they start with Ash having some kind of encounter with each character. For example, he might save a girl from a wild Pokemon, which starts their connection. Then, as they travel together, their relationships grow. They might share moments of training Pokemon together, or having deep conversations around the campfire at night.
It really depends on the specific harem fanfic. Sometimes, Ash's betrayal might be a misunderstanding. He could be seen as betraying the harem when in fact he was trying to protect them. However, the girls in the harem don't realize this and think he has turned his back on them. This sets up a lot of drama and tension in the story as Ash has to find a way to clear up the misunderstanding and regain the trust of the harem members.
One common theme is friendship. Despite the harem aspect, the relationships often start from a place of friendship. For example, Ash might be friends with different characters first and then the harem - like situation develops.