Another way to develop the time quirk is to introduce new applications. Besides freezing and traveling back in time, he could discover that he can accelerate time in a small area. This would be useful for things like quickly healing wounds (by accelerating the body's natural healing process) or making plants grow faster to create barriers or hiding places. The development of these new applications could come from his experimentation, his encounters with other characters who have knowledge about quirks, or even from his dreams and subconscious exploration of his quirk's potential.
It could be developed by having Izuku practice and gradually increase the duration of his time - freezing ability. For instance, at first, he can only freeze time for a split second, but with training, he can hold it for a few seconds, which makes a huge difference in combat.
The quirk could also develop in terms of its range. Initially, it only affects a small area around him, but as the story progresses, he learns to expand the range so that he can freeze time for a whole battlefield or even an entire city block. This development could be tied to his emotional growth and understanding of his quirk. Maybe when he overcomes a major obstacle or has a deep realization about himself, his quirk's range expands.
His relationship with All Might would also be affected. All Might might be more cautious about Izuku's quirk as it's very powerful and could potentially disrupt the fabric of time. Izuku, on the other hand, could use his quirk to go back and learn more about All Might's past, which could strengthen their bond as he gains a deeper understanding of his mentor. However, it could also create a rift if Izuku discovers something in the past that he doesn't like about All Might's actions.
One idea could be that Izuku's time quirk allows him to briefly freeze time during battles. This gives him an edge in strategizing and attacking his opponents when they are immobilized.
Izuku could develop by learning to accept his vampire quirk. At first, he might be scared or ashamed of it, but as he realizes the potential it has for good, he grows more confident. For example, when he saves someone using his vampire - enhanced abilities.
One idea for Izuku Midoriya's quirk in a Dark Souls - inspired fanfiction could be 'Soul Link'. This quirk would enable him to form a link with other people's souls. He could use this link to either heal them by sharing his own energy (similar to Estus Flasks in Dark Souls), or he could disrupt their soul's energy, causing them to be weakened or even stunned. It could also work as a way for him to sense the presence and intentions of others, as he would be attuned to their souls. This quirk would give him a unique advantage in battles and also in forming relationships with other characters in the fanfiction.
A great way to develop their relationship is through shared traumas. Maybe they both had a difficult experience during a villain attack. They could open up to each other about their fears and insecurities during that time. This vulnerability would bring them closer together. Additionally, they could participate in a hero competition together. As they face tough opponents, they encourage each other and celebrate their victories, which deepens their bond.
He could start by training to absorb more types of energy. For example, if he can currently only absorb physical energy like kinetic or thermal, he could learn to absorb electromagnetic energy too. This would open up new possibilities for his quirk usage. Another way is to increase the efficiency of his absorption. Maybe he can work on reducing the time it takes to absorb energy or increase the amount he can hold at once.
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.
One idea could be that Izuku discovers his time manipulation quirk late. For example, during a really tough battle against a powerful villain where all seems lost. He accidentally activates the quirk and rewinds time just enough to change the outcome. This could lead to a whole new arc of him training to control this powerful and dangerous quirk.
In a fanfiction with a Dark Souls - inspired quirk for Izuku Midoriya, his character development would be a journey of self - discovery. For instance, if his quirk was 'Grim Resolve', which gives him a boost in strength and speed when he's in a near - death situation (similar to the 'hollowing' concept in Dark Souls), he would have to learn when to push himself to that limit. He would start off as a naive and somewhat idealistic character, but as he experiences the harshness of his quirk and the battles he has to fight, he would become more cynical. But at the same time, he would also find a deeper sense of purpose. His interactions with his classmates and mentors would change as they try to understand and help him with his unique quirk, and he would grow into a more complex and mature character as a result.
His relationships with his friends would likely become more complex. If he starts using his time quirk to change things, his friends might not remember the original timeline, but Izuku would. This could create a sense of isolation for him as he holds memories that no one else does.