Often, in these fanfictions, Izuku discovers his fire and ice quirk in an unexpected way. Maybe it's a late - blooming quirk that suddenly emerges. There's usually a mentor figure, either an existing character like All Might or a new character, who helps him understand and develop his quirk. And a big part of the plot is how he uses his unique quirk to overcome villains in creative ways that the normal Izuku in the original series couldn't do.
In many of these fanfics, the relationship between Izuku and his classmates changes. Some might be jealous of his powerful quirk, while others might be in awe. There are often plotlines where Izuku has to prove himself not just to his enemies but also to his friends. His fire and ice quirk also sometimes has a deeper connection to his family or his past, which is gradually revealed as the story progresses. For example, it could be a quirk that was passed down in his family but was thought to be lost, and now he has to carry on the legacy while dealing with the challenges it brings.
One common plot element is Izuku struggling to control his dual - natured quirk at first. Since fire and ice are opposite elements, it's a challenge for him to balance them. Another is that he might face discrimination or suspicion from others who are afraid of his powerful quirk. Also, there could be a lot of training montages as he tries to master using both elements effectively.
Well, a great plot could be Izuku's journey to master his fire quirk. He might seek out a retired hero with a fire - related quirk to train him. Along the way, he discovers that his fire quirk has a unique property, like it can burn through certain types of energy shields that most other quirks can't. This makes him a target for villains who want to study his quirk, and he has to fight to protect himself and his secret.
You can start by looking on popular fanfiction websites like Archive of Our Own (AO3). Just search for 'Izuku fire and ice quirk' in the search bar, and it'll show you a bunch of relevant stories. There are also some good ones on Fanfiction.net, but the tagging system there might require a bit more digging.
Another plot point is how the wing quirk affects his relationships. His friends might be in awe or a bit jealous. In some stories, his new quirk can cause some tension with Bakugo as Bakugo sees it as another way Izuku is getting special treatment. And also, the hero training aspect. Teachers like All Might have to come up with new training methods to help Izuku master his flying abilities.
In a fanfiction, the development of Izuku having a black fire quirk can be really multi - faceted. First, the visual aspect of the quirk can be described in detail. The black fire could have a smoky, otherworldly look that sets it apart from normal fire. Emotionally, Izuku could struggle with the fact that his quirk is so different from what he expected. He might feel like an outcast among his peers. Then, there could be a story arc where he discovers a hidden power within the black fire quirk. For instance, he might find out that it can absorb other forms of energy. This would not only make his quirk more powerful but also open up new storylines about him learning to use this new aspect and facing new enemies who are interested in his unique ability.
A common plot device is the discovery of a new training method. This often leads to Izuku's quirk upgrade. For example, he might find a secret training ground where the conditions are perfect for pushing his limits. Another is the introduction of a new character who has knowledge about One For All that Izuku didn't know before.
One implication could be a change in his relationships. His friends might be initially afraid or distrustful. For example, Bakugo could see this as a sign of Izuku being a real threat now, instead of just a rival. Also, the teachers at UA might have to deal with a whole new set of problems regarding Izuku's training and control of his dark quirk.
A sentient quirk for Izuku in fanfiction could have a huge impact on the plot. It could be a source of both power and trouble. For instance, villains might try to target the quirk specifically, seeing it as a valuable asset or a threat. Izuku would have to constantly protect it while also using it to his advantage. The quirk could also communicate with other sentient entities in the fanfiction world, opening up new storylines and alliances.
The 'Mentor Figure' trope is also quite common. Given the power of the lightning quirk, Izuku usually needs someone to guide him. This could be an older hero or even a mysterious stranger. The mentor helps him understand his quirk better, trains him in combat techniques that are specific to his lightning - based powers, and also gives him moral support. This trope adds depth to the story as it shows Izuku's growth not just in terms of power but also in character.
One common theme is self - discovery. Izuku often has to figure out the full extent of his healing quirk, which is a journey of self - exploration.
In izuku sunshine quirk fanfiction, the theme of discovery is common. Izuku discovers new aspects of his quirk as he progresses. Also, the theme of acceptance is there. He has to get others to accept his rather unique quirk, and at the same time, he has to accept the responsibilities that come with it. The fanfictions may also touch on the theme of redemption, where Izuku uses his sunshine quirk to bring about positive change in characters who have gone astray.