Well, Harry is bound to be a central figure in this fanfiction. And since it's about 'Lucifer reborn' in relation to Harry, it's possible that there could be characters who are either allies or enemies of this new Harry - Lucifer entity. There might also be some original 'Harry Potter' characters like Dumbledore or Voldemort who play important roles in the story, perhaps having to deal with this new and changed Harry.
Obviously, Harry Potter would be one of the main characters. And then there would be Lucifer. Depending on the story, characters like Hermione and Ron might also play important roles as they interact with Lucifer in the wizarding world.
Obviously, Harry is one of the main characters as he is the vessel. And Lucifer, of course, is a key figure as his essence is involved with Harry. There might also be other characters from the original Harry Potter universe, like Hermione and Ron, who could be trying to deal with the situation of Harry being Lucifer's vessel.
Obviously, Harry (reborn as a character in the Naruto world) is a main character. Naruto himself is also a key figure as Harry will interact with him. Sasuke could also be important as he is a central character in the Naruto series and his relationship with Naruto and any new character like Harry will play a role in the story.
Well, obviously Lucifer and Chloe are the main characters. Lucifer, with his devil - like charm and powers, and Chloe, the detective. Their marriage is the central focus, so they are the ones around whom all the stories revolve.
In this fanfiction, the idea of Harry being reborn as something related to Lucifer can bring about a whole new set of relationships. For example, his relationships with his friends like Ron and Hermione might change drastically. He could be seen as an outcast because of his new 'Lucifer - like' nature. The story could explore how he copes with this new identity, and whether he uses it for good or succumbs to the darker side often associated with Lucifer. It could also involve new magical elements that are a blend of Harry's original magic and Lucifer - inspired powers.
Also, there could be new characters introduced, such as archangel mentors or other celestial beings. These new characters would help shape Harry's journey as an archangel, teaching him about his new powers and the responsibilities that come with being an archangel.
Obviously, Harry as the reborn Black would be a main character. Sirius Black would probably also play a major role, as he's an important part of the Black family. And Bellatrix Lestrange could be another key character, her relationship with the Black family and her own dark nature would create a lot of interesting interactions with Harry in his new identity.
Obviously, Harry Potter is the main character since it's about him being reborn as a Peverell. There might also be characters like Hermione and Ron who are likely to be involved in his new journey, supporting him or being intrigued by his new identity.
Obviously, the four founders - Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw and Salazar Slytherin are main characters as they are being reborn. They bring their unique personalities and magical abilities back to the story.
Sometimes other characters from the 'Lucifer' series can also play important roles. For instance, Amenadiel might get involved. He could be trying to stop Lucifer from doing something he believes is wrong, or he might have his own reasons for getting in the middle of the situation. Maze could also be there, either helping Lucifer or Chloe depending on the story's direction.