Wonder Woman would be a great choice. She's a strong, iconic character. Her sense of honor and justice could be drawn to Ben's own heroics. Another could be Harley Quinn. Her chaotic nature might be interested in Ben's wild alien forms and adventures. And of course, Supergirl. Her superpowers and kind heart could make for an interesting dynamic with Ben.
Wonder Woman would be a great choice. She is strong, noble, and would be an interesting contrast to Ben's more impulsive nature. Her Amazonian upbringing and values would add depth to their interactions.
One idea could be Ben Tennyson getting transported to the DC universe and his Omnitrix's powers attracting the attention of various female characters. For example, Wonder Woman might be intrigued by his unique abilities and his sense of justice. Another could be that he teams up with some of the female superheroes to fight a common enemy, and during the process, a harem - like relationship starts to form.
Well, in 'Ben 10 Harem Fanfiction', Ben is a central character for sure. Then there are characters like Julie, who was his girlfriend in the original series. Also, some alien forms that Ben can transform into might be personified and added to the harem in some fanfictions.
Well, Ben is obviously one of the main characters. He brings his unique set of alien powers to the story. Then there are the vampire characters in the harem. Each vampire could have their own distinct personality, like a sultry and mysterious female vampire who is the leader of the harem, and a young, naive vampire who Ben has a special bond with.
Well, Wonder Woman is an obvious choice. Her strong - willed and noble nature would be an interesting contrast to Naruto's more free - spirited ninja self. Another could be Zatanna, with her magic abilities. She might be curious about Naruto's chakra - based techniques which are somewhat similar to magic in a way. And then there's Starfire, whose alien nature and exuberant personality could lead to some fun interactions with Naruto.
One idea could be that Ben, with his Omnitrix, somehow gets transported to the DC universe and meets various female characters. Maybe he has to team up with them to stop a common threat, and during the adventure, relationships start to form. For example, he could work with Wonder Woman, and she is initially skeptical of his powers but grows to respect him.
Gwen could be one of the characters in the harem. She already has a close relationship with Ben in the original series. Another could be Kai Green. She's shown interest in Ben before and could easily be part of a harem in a fanfiction. Also, female aliens like Rook's sister (if she exists in the fanfic's version) could be part of it.
One popular Ben 10 Ben Harem fanfiction could be those that focus on Ben's adventures with his harem while facing new alien threats. For example, a story might have Ben and his harem working together to stop an evil alien warlord from taking over the Earth. They use their combined powers and skills to outwit the enemy.
One popular OC is a female alien with telekinetic powers. She stands out because her powers are both useful in combat and in helping Ben solve problems. Another is a human girl who is a tech - genius. She can upgrade Ben's alien devices and often comes up with clever plans. There's also an OC that is a shape - shifter from a previously unknown planet, which adds an element of mystery to the harem.
Most likely Ben Tennyson would be the main character since it's about him unlocking the master control. His grandpa Max and cousin Gwen might also be important characters as they are often involved in Ben's adventures in the Ben 10 universe.