Most likely Sonic and Tails would be main characters. Since it has 'tails raised' in the title, Tails is clearly important. And Sonic is often the central figure in Sonic - related fanfictions.
There could also be other characters like Knuckles. He might be involved in the story, perhaps helping Sonic and Tails in their adventure. Maybe he's the one who first notices Tails' raised tails and realizes something unusual is going on. Or it could be Amy, who might be there to provide some emotional support or be part of the group facing the challenges.
Sonic is often paired with Tails. Their friendship in other Sonic canons carries over, and in Sonic Underground fanfiction, they might have new adventures together. Sonic's speed and Tails' smarts make them a great team.
In this fanfiction, there could be other characters like Knuckles. He might be involved in trying to stop Tails if he's causing trouble. Amy could also be there, perhaps trying to use her compassion to reach out to Tails. And of course, there might be some new, original characters created specifically for this fanfiction, like a mysterious figure who has influenced Tails' turn to the dark side.
In 'baby tails sonic fanfiction', the two main characters are, without a doubt, Baby Tails and Sonic. Baby Tails is often portrayed as an innocent and curious character. Sonic, on the other hand, is the more experienced and heroic figure. They are the core around which the story revolves. However, we may also see the appearance of other Sonic characters like Cream the Rabbit or Rouge the Bat in some fanfictions, but their roles are usually secondary compared to Baby Tails and Sonic.
The main characters are obviously Tails and Sticks. Tails is the smart, two - tailed fox with a knack for inventing. He's always coming up with new gadgets to help in their adventures. Sticks, on the other hand, is the wild and somewhat paranoid but highly skilled jungle badger. She has great survival instincts and is not afraid to get her hands dirty in a fight or when exploring the unknown.
In this 'tails raised by sonic fanfiction', it might also show Tails in a situation where he has to face a new challenge. His raised tails could be a sign of his determination. For example, he could be up against a new villain who has some sort of power over the environment. Tails' raised tails would be like a signal that he's ready to use his skills, such as his mechanical knowledge and flying ability, to overcome the situation.
It could be a new villain created just for this fanfiction. Maybe a powerful wizard who wants to use the combined powers of Sonic Underground and Tails for his own dark magic. He sees their unique abilities as a way to gain ultimate power and they have to fight against his spells and minions.
Well, clearly Tails and Wave are the main characters. Tails, with his intelligence and mechanical know - how, and Wave, known for her speed and agility.
I'm not sure specifically as it depends on how the fanfiction author has developed the story. But it's likely that some of the main characters from the original Uzumaki story would still play important roles. For example, characters like Uzumaki Naruto or Uzumaki Kushina might be central figures, as they are iconic in the Uzumaki clan.
The main characters are, of course, Tails and Shadow. Tails is known for his intelligence and mechanical skills. He is a fox with two tails which he can use to fly. Shadow, on the other hand, is a powerful and often brooding character with super - speed and strength.
Well, Sonic is the central figure. But other characters like Amy Rose could be important. She might be heartbroken to see Sonic turn dark and try to use her love for him to bring him back. There could also be some new characters created specifically for this fanfiction. For example, a mysterious character who has the power to either make Sonic darker or has the key to bringing him back to normal.