One possible new power could be energy projection. He could shoot out webs of energy instead of just the physical webs. This would not only enhance his offensive capabilities but also give him a new way to interact with his surroundings and immobilize foes from a distance.
His super strength could easily disrupt the past. For example, if he's not careful while trying to stop a crime, he might accidentally cause more damage than good. He could break things that were important in the original timeline.
Another way Ichigo could get his powers back in fanfiction is through a magical or spiritual artifact. Maybe he discovers an ancient sword or a talisman that has the ability to restore his lost powers. This could be part of a grander plot where he has to go on a quest to find this item, facing various challenges and enemies along the way. During this journey, he might also learn more about the true nature of his powers and how they are connected to the overall 'Bleach' universe.
Spider-Man got his powers after being bitten by a radioactive spider. This gave him enhanced strength, agility, the ability to climb walls, and a 'spider sense'.
He might first go into denial. He could keep trying to do the things he used to do with his powers, like swing from building to building, only to fall. Then he could start to rely on his intelligence more. Since Peter Parker is a smart guy, he'd use his scientific knowledge to try to find a way to get his powers back. He may also look for allies who can help him, like other superheroes or scientists.
One reason could be a powerful magic spell cast on him by a villain. For example, a sorcerer who wants to stop Spider - Man from interfering in his evil plans might use a spell that disrupts the source of his powers. Another possibility is that he gets exposed to some sort of radiation or chemical that nullifies the mutation that gives him his powers. Maybe he enters a new dimension where the laws of physics are different and his powers don't work there.
One way could be through a magical encounter. Maybe he stumbles upon an ancient artifact that has the power to restore his abilities. It could be a relic from his home planet that he discovers by chance.
Well, Spider Man often uses his powers in creative ways during his interactions. His agility allows him to easily navigate through a busy city street full of people without bumping into anyone. If there's a local fair, he can use his web to create a fun little ride for the kids, like a makeshift swing. His ability to climb walls can be useful when he's helping a window cleaner who's stuck on a high - rise building. He climbs up, rescues the cleaner, and then gives him some tips on safety. He also uses his powers to show off a bit sometimes, which always amazes the citizens and makes them cheer for him.
Rocket could be another helper. With his technical expertise, he could build a device or figure out a scientific solution to bring back Peter's powers. He's always been good at tinkering with things.