The main antagonist would likely still be the Joker himself. Even with the addition of the bone weave, he is the one causing chaos and destruction in Gotham. His actions are what drive the conflict in the story.
If we consider the fanfiction in a different light, perhaps a new character could be introduced as the main antagonist. For example, someone who also wants the bone weave for their own purposes. This character could be a powerful sorcerer who sees the bone weave as a key to ultimate power. So they start to fight the Joker for control of the bone weave, and in the process, also cause trouble for Batman and the city of Gotham.
Well, perhaps in this fanfiction, the Joker is given the bone weave by an unknown entity. He then starts to incorporate it into his appearance. He weaves the bones into his clothing and even his hair, creating a truly terrifying look. He then uses the bone weave to intimidate the citizens of Gotham. He also might find that the bone weave has some connection to an ancient Gotham legend, which he then uses to spread chaos and fear throughout the city.
Well, it could also create some conflict. If the bone weave is an experimental or rare technology, there might be those who oppose Joker getting it. This could lead to internal strife within the crew or between different factions in the Mass Effect universe. It might also attract unwanted attention from enemies who want to study or steal the bone weave technology from him.
The idea of Joker getting bone weave in a fanfiction could open up a lot of story possibilities. For example, it might change his relationship with the other characters. If he becomes stronger or has some new abilities because of it, the crew of the Normandy could react in different ways. Some might be jealous, while others could be concerned about the potential risks or how it might change his personality.
The 'joker gets heavy bone weave fanfiction' could be centered around a very imaginative and perhaps dark concept. The Joker, being a chaotic and unpredictable character, if he gets a 'heavy bone weave', it could be part of a plot where he gains a new and menacing ability. Maybe the 'heavy bone weave' gives him enhanced strength or some sort of strange defense mechanism. It could also be a key part of a new story arc in the fanfiction, where his actions with this new acquisition drive the plot forward, causing chaos and disruption in the fictional world he inhabits.
Finding the 'joker gets heavy bone weave fanfiction' might be a bit of a challenge. First, check the major fanfiction platforms. However, if it's a relatively new or niche piece, it might not be on the most well - known sites. You could also try searching for related forums or communities dedicated to the Joker or the source material (like Batman if that's relevant). Sometimes fans share their work in these more specialized spaces.
Another option is a group of anti - magic fanatics. They view Percy's wings as an abomination because they are a result of magic. They hunt Percy down, believing that by getting rid of him and his wings, they are protecting the world from the 'evils' of magic.
It could still be Hawk Moth. Since Nathalie has been working with him, getting a Miraculous might make her a threat to his plans, so he could turn against her and become the main antagonist.
It could be a long - lost relative of an old enemy. For example, if there was a powerful dark wizard that Natsu defeated in the past, this relative might come seeking revenge and be powerful enough to kill Natsu.
Maybe an evil artist from another dimension. This artist is jealous of Nathanael's pure creativity and the unique power of his miraculous. They come to Nathanael's world to steal his ideas and use his miraculous for their own dark purposes, like creating chaos and destruction through art.
Maybe the main antagonist is an old enemy of Robin's who becomes jealous of his new powers. This enemy then devises a plan to steal Robin's powers or at least neutralize them so that he can regain his former status as the top threat. He could be a powerful martial artist or a criminal mastermind with a large network of henchmen.