Superman could be an interesting addition. His superpowers and moral stance would contrast and interact with Batman in many ways, creating a lot of drama and action.
Perhaps a character like Zatanna. Her magic abilities would add a new element to the Batman universe in the fanfic. She could be a powerful ally or a mysterious figure that Batman has to figure out, and her presence would surely change the dynamics of the story.
The Riddler from a different timeline or dimension. He could bring new and more complex riddles, and his relationship with Batman could be re - explored in a fresh context within the 'batman impregation fanfic'.
One possibility is a young girl who has the ability to control light in a way different from Ruby's speed. She could be a street urchin who has been surviving on her own in the slums of a major city in Remnant. When she meets the RWBY team, she initially distrusts them but eventually becomes an important part of their group. Also, a grizzled old veteran of many battles against Grimm could be added. He could be a mentor figure, teaching the RWBY characters new combat techniques and sharing his wisdom about the history of Remnant and the Grimm.
There could also be a group of street - smart kids who befriend the Baudelaires. They have their own set of skills and stories, and together they can form a sort of alliance to protect their neighborhood from any potential threats. These new characters would bring in fresh perspectives and interactions for the existing characters in the fanfic.
You could add a young and inexperienced vault hunter who is eager to make a name for themselves. They might start off as a bit of a nuisance to the more experienced characters but gradually prove their worth. There could also be a mysterious merchant who is not what they seem. They might have a hidden agenda and be involved in some sort of illegal trading that could have a big impact on the Borderlands economy.
An old - fashioned Pokemon breeder who has a deep connection with the traditional ways of raising Pokemon. They could provide the main characters with valuable advice on how to make their Pokemon stronger and healthier. However, they might also be a bit stubborn about sticking to the old ways and this could cause some conflicts with the more modern - thinking characters in the fanfic.
A young mage who has the power to communicate with all types of magical creatures, not just dragons. This mage could be a valuable ally or a source of trouble for the existing characters in the fanfic.
A magical tutor for Harry's kids could be an interesting addition. This tutor could have some really unique magical abilities and a mysterious past. Maybe a young witch from a far - off land who brings new spells and cultural elements of magic to the story.
A young apprentice who has just started working in the chocolate factory. He is eager to learn from Willy Wonka but often makes mistakes that lead to humorous situations. For example, he accidentally mixes up the ingredients for a very important chocolate and creates a new, strange - tasting but oddly popular chocolate.
A scientist who is an expert on alien plants. He could be brought in to study the plant and try to find a way to control it.
One potential character could be a wise old hermit who lives in a secluded part of the paradise. He could offer Percy valuable advice and knowledge about the secrets of the paradise.
One interesting concept could be new character integrations. For example, introducing a character from another universe into the Batman fanfic world. This can create unique storylines and interactions.