The new quirk of Deku is quite exciting and adds a new dimension to his powers. But I don't want to spoil it for you. You should read the manga to find out!
Perhaps an ancient artifact in the MHA world has the power of the Naruto toads sealed within it. A villain discovers it first but a young hero - in - training manages to steal it away. Once in their possession, they unlock the toad quirk. They would then need to train hard to master it, just like Naruto did. They could call on the toads for help in battles, use their strong physical attacks and even learn some of the toad - related ninjutsu, adapting it to fit the rules and physics of the MHA world.
They would be very powerful. Just like Naruto can summon giant toads, this character could summon toads in the MHA world. They could use the toads as mounts or have them fight alongside. For example, they could have a toad use its tongue to grab villains and hold them in place.
Tsuna's quirk, if we assume his Dying Will Flames are his quirk in the MHA universe, would likely be classified as an emitter type quirk. He could use his X - Burner attack as a long - range offensive move against villains. His hyper intuition could also be a part of his quirk, allowing him to predict his opponents' moves in battle. This would make him a valuable asset in hero teams, especially in complex battles where strategy is key.
He could have a quirk like 'Enhanced Intellect', which would further boost his already incredible detective skills. This would make him able to analyze situations even faster and come up with strategies on the fly.
One great MHA time travel fanfic is 'Back to the Start'. It has an interesting plot where the main character goes back in time and tries to change certain events in the MHA world. The character development is really well - done in this one.
Another important aspect is the writing style. It should be engaging and easy to follow. A complex time travel plot can quickly become confusing if the writing isn't clear. The author should be able to set the scene well, whether it's the past or the present in the MHA universe. And the fanfic should also have some sort of emotional depth, like the character's feelings about being in a different time and how they deal with the knowledge they have from the future.
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.
His quirk could be something like super - speed regeneration. In the original Naruto series, he has a great deal of stamina and the ability to heal relatively fast. But with this quirk, he could recover from even the most severe injuries in seconds. This would mean he could keep fighting no matter how badly he was hurt, and his enemies would find it extremely difficult to defeat him.
Bakugo is often paired with Izuku. Their relationship is complex in the original series, and in fanfiction with Izuku's time quirk, it could add more depth. Bakugo might be jealous of Izuku's new power at first but then come to respect it as they face challenges together.