The Pokémon professors, like Professor Oak, would be very positive about it. They would see it as a new chapter in Ash's life and look forward to seeing how their combined knowledge of Pokémon would grow. Other trainers might be inspired. Younger trainers would look up to them as a power couple in the Pokémon world. Some of the more competitive trainers might initially be envious but would eventually respect their relationship. The various Pokémon gym leaders would send them gifts as a sign of congratulations and hope for a friendly Pokémon battle in the future.
Ash's friends like Brock and Misty would be really happy for him. Brock might offer some relationship advice based on his own experiences. Misty would probably be a bit jealous at first but then be supportive. Lillie's family would be overjoyed. Her mother would be proud to see her daughter start a new life with Ash. And the Pokémon they have befriended would sense their happiness and be more affectionate towards them.
Some of Ash's more competitive Pokémon, like Charizard, might be a bit protective at first. It might see Lillie as someone who could take Ash away from their adventures. But once it realizes how happy Ash is, it would warm up to the idea. Lillie's Pokémon that are more timid, like the Mareanie she has, might be a bit shy around all the new people and Pokémon at the wedding, but still be happy for their trainer.
Pikachu would be super excited. It has been with Ash for so long and would see Misty as part of the family. It might play more with Misty's water - type Pokémon. Misty's Starmie could be very protective of the new family unit and use its psychic powers to help around the house sometimes.
In many Pokemon fanfictions, the idea of Ash and Lillie getting married is quite interesting. Some fanfictions might focus on their adventures together that lead to their deepening relationship and ultimately marriage. It could start with them traveling through different regions, facing challenges side by side, and gradually realizing their feelings for each other. This would be a really sweet and heart - warming story for Pokemon fans who support this pairing.
Ash would be extremely hurt. He's a very loyal person, and having someone he cares about like Lillie betray him would be a huge blow. He might initially go into denial, not believing that Lillie could do such a thing.
At first, his Pokémon would be startled. They've always known Ash as a human. But then, they would start to adapt. Some Pokémon, like Squirtle, might try to play with Ash in his new form, thinking it's a new kind of game. However, his more loyal Pokémon, like Greninja, would be determined to find a way to turn Ash back. Greninja might use its special bond with Ash to try and communicate with him on a deeper level in this new form, to understand what happened and how to reverse it.
Pikachu would probably be very excited. It might jump around Ash, making little electric sparks of joy. Bulbasaur could bring Serena some fresh berries it finds in the forest as a sign of care. Eevee, if they have one, might curl up next to Serena's belly, as if protecting the unborn baby. Their Pokémon would sense the importance of this new development and do their best to be helpful and protective.
The professors in the Pokémon world, like Professor Oak, would likely be concerned but also offer their wisdom. They could provide resources or knowledge about how to take care of a pregnant woman in the Pokémon world. The other trainers that Ash and Bonnie know might have a mix of reactions. Some might be supportive, while others might spread rumors or be jealous. Overall, the reactions would add a lot of drama and depth to the fanfiction.
Some of his Pokémon might be very confused and sad. Pokémon like Pikachu, who has been with Ash for a long time, would probably miss the adventures and battles they had together. Pikachu might try to cheer Ash up and convince him to change his mind.
One plot twist could be that a powerful Pokémon villain tries to stop the wedding to use their combined power for evil. Another could be that a long - lost relative of either Ash or Lillie shows up with a secret that shakes their relationship. Maybe a prophecy is revealed that their union will have unforeseen consequences for the Pokémon world.
Sakura might be a bit surprised at first, but she would probably come around and be happy for Naruto. Sasuke would likely be indifferent on the surface but secretly hope that Naruto is making the right choice. Hinata might be a bit sad that Naruto didn't choose her, but she would be polite and congratulate them.