Conflict between different moralities also frequently appears. The new world he crosses into may have different values and ethics compared to his own. His 'evil' side might be more in tune with some aspects of the new world while his original heroic side clashes with others, creating a complex web of moral dilemmas.
Well, perhaps Asta could be corrupted by a powerful dark magic artifact. He might start to see his friends as obstacles in his quest for power and turn against them.
One popular 'evil asta crossover fanfiction' could be one where he crosses over with a character from another shonen series like Naruto. In such a fic, Asta's dark side might interact with Naruto's determination in interesting ways, perhaps leading to a battle of ideologies between the two worlds.
It could be Yuno. Normally they are friends, but if Asta turns evil, Yuno might be the one to oppose him. Yuno has his own strong magic and a sense of justice that would make him a natural adversary.
A potential plot could be Asta's slow descent into darkness. He starts off as a bit more cynical after facing continuous rejections. Then, he meets a group of outcasts who have also been wronged by the system. They convince him that the only way to make things right is to take power by force. Asta begins to use his anti - magic to steal magic from other mages, believing it's a way to level the playing field. As he does this, he becomes more and more feared and is seen as a threat to the kingdom.
Since lemon fanfics are inappropriate, we should focus on their general characteristics from the official story. Asta is highly determined and energetic, always striving hard despite his lack of magic initially. Yuno, on the other hand, is more calm and has a natural talent for magic. They both have a strong bond as rivals and friends.
One way Asta could turn evil in a fanfiction is if he was constantly ostracized for his lack of magic in a more extreme way. For example, if the Magic Knights not only rejected him but actively bullied him. This could lead to a build - up of anger and resentment. Eventually, he might decide that the system that has shunned him is wrong and needs to be overthrown, leading him down an 'evil' path of using his anti - magic to cause chaos rather than protect.
Asta in an elf fanfic might be the protagonist. He could be on a quest, perhaps to save the elves from some great danger or to discover a hidden secret within the elven realm. He might form alliances with different elven clans and face many challenges along the way, like fighting against dark magic or evil creatures that threaten the elven way of life.
Asta and Yuno are childhood friends in a magical world. They both strive to become powerful wizards and fulfill their dreams. Their paths are filled with challenges and adventures.
Noelle could be a great addition. Her water magic is quite powerful and she has a complex relationship with both Asta and Yuno. She could be a source of both support and conflict in the fanfic. Another good character is Luck. His lightning magic and his rather unpredictable nature can add a lot of action and excitement to the story.