In fanfiction, if The Powerpuff Girls met Superman, there could be an epic battle at first. The Powerpuff Girls are used to being the top defenders in their city, and Superman is a powerful hero. But then they might realize they have a common goal of protecting the innocent. They could team up and use their combined powers to face a huge threat like an alien invasion. Superman's super strength and flight, along with the Powerpuff Girls' unique abilities like Blossom's ice - breath, Bubbles' sonic scream, and Buttercup's tough fighting skills, would make them an unbeatable force.
A unique story could involve a role - reversal. Instead of Superman being the experienced hero, the Powerpuff Girls are the ones who know more about a particular threat in their city. Maybe there's a villain that uses a type of kryptonite - like substance that only the girls know how to handle. So, Superman has to rely on them for help. This flips the typical dynamic of the more powerful and experienced hero coming to the rescue.
Superman is extremely powerful on his own. His powers are almost god - like. But the Avengers have a lot going for them too. For example, Iron Man has his high - tech suits which can adapt to different threats. Captain America is a great strategist. In a fanfiction, it could depend on the circumstances. If it's a fight in an environment full of kryptonite, the Avengers would have an advantage. But in a normal battle, Superman's power might be too much for the Avengers to handle all at once.
Well, obviously the main characters would be the Powerpuff Girls - Blossom, Bubbles, and Buttercup. And Sonic the Hedgehog would also be a central character. There could also be other characters from both universes like Professor Utonium from the Powerpuff Girls side and Tails or Knuckles from Sonic's side depending on the direction of the fanfic.
In the powerpuff girls blossom story, Blossom is the central figure. However, other significant characters include her two sisters. Bubbles, who is sweet and has the power of sonic scream among others, and Buttercup, the tough and feisty one. Additionally, Professor Utonium, their creator, also plays a role in the story. And then there are the villains. Mojo Jojo is a recurring bad guy, always trying to outwit the Powerpuff Girls. There are also other villains like Fuzzy Lumpkins who add to the challenges that Blossom and her sisters have to face.
Maybe Professor Utonium could be a good babysitter. He already knows the Powerpuff Girls very well, their strengths and weaknesses. He created them, after all. So he would be able to handle any situation that might come up while babysitting them, whether it's dealing with a monster attack or just making sure they eat their vegetables.
Another character that might be considered important in some of the stories could be Mojo Jojo. He's always trying to cause trouble for the Powerpuff Girls. His evil plans and his rivalry with the girls often drive the plot forward in many of the Lemon Stories.
It's likely that the main characters would be the Powerpuff Girls (Blossom, Bubbles, Buttercup) along with Bliss. Since it's related to the Powerpuff Girls and has 'Bliss' in the title, they all probably play significant roles.