The title 'dark meets another tenshi fanfiction' suggests that the two main characters are 'dark' and 'another tenshi'. However, in fanfiction, sometimes there are side characters that end up being just as important. Maybe there'll be a friend of 'tenshi' or an enemy of 'dark' that will add depth to the story. But as of now, just from the title, it's 'dark' and 'another tenshi' that seem to be in the spotlight.
Based on the title, the main characters are likely 'dark' and 'another tenshi'. But without reading the fanfiction, it's hard to say if there will be other important characters that play significant roles in the story.
Clearly, from the title 'dark meets another tenshi fanfiction', 'dark' and 'another tenshi' are the main characters. 'Dark' might be a character with a shadowy or complex nature, while 'another tenshi' could be some sort of angel - like or positive - natured character. But it's also possible that there are other characters who are not mentioned in the title but will be introduced as the story progresses, perhaps a mentor figure for one of them or a common foe that they have to face together.
The other Tenshi would be a main character as well. She might bring new powers or a different view of the angelic side compared to what we've seen before in the D.N. Angel series.
I think from 'dark meets another tenshi fanfiction', we might see a unique world - building. Since it's a fanfiction, it could take the original concepts related to 'tenshi' and add a new twist with the 'dark' element. It could show how these two elements interact in a fictional setting, like in a magical or other - worldly place.
A third storyline could be that there is a mystery surrounding the new Tenshi. Dark is drawn into it as he tries to figure out who she really is. Along the way, they encounter various obstacles and challenges, both physical and emotional, that test their relationship and their own identities.
Since I don't know the 'time tenshi story' well, I can't say for sure. But likely the angel would be one of the main characters.
There is a girl who plays a significant role. She is often at the center of the events that unfold in the story.
I don't know the main characters as I haven't read the 'otonari no tenshi web novel'.
I'm not sure as there's not enough information given. It could be new characters specifically created for this 'Another Story' related to the dark slime.
It's hard to say exactly who the Dark One is without reading the fanfiction. It could be a villain from another universe that somehow crosses paths with Naruto. Maybe it's a character with a tragic past that turned to the dark side, and now Naruto has to deal with the consequences of that. It could also be a symbol of all the darkness in the Naruto universe that has been given a physical form to create a more interesting conflict for Naruto.
Sometimes other characters can also be important. For instance, Piccolo from Dragon Ball might show up to give Gohan some advice or help in the fanfiction. In the Naruto side, Sasuke could also be involved, perhaps starting off as an antagonist to the new team - up of Gohan and Naruto, but then later joining them. Also, characters like Bulma from Dragon Ball could play a role, maybe she creates some device that helps in the story, like a way to translate between the Saiyan and ninja languages.
The main characters are Stiles and the Cullens. Stiles is known for his ability to adapt in strange situations. When he meets the Cullens, their interactions will be centered around how they deal with each other's differences. The Cullens' vampiric abilities and Stiles' human (or whatever he is in his original context) nature will play a big part in their relationships in the fanfiction.