Well, in some fanfictions, when Five gets hurt, it shows his vulnerability. For example, if he's been in a fight and is badly injured, his usual tough exterior cracks. His siblings might start to see him in a new light, not just as the time - traveling badass but as someone who can be broken too. This shift in their perception of him can be a very emotional aspect in the fanfiction.
Some fanfictions might have a plotline where Five is hurt because of his own reckless behavior. He's a complex character who sometimes dives headfirst into dangerous situations without fully thinking things through. So, he could end up hurt as a result of his own impulsiveness. Also, there could be a plotline where Five is hurt emotionally by his family's lack of understanding or acceptance of him, which then leads to some sort of physical or mental breakdown.
Well, I'm not sure about specific 'The Umbrella Academy Five Hurt' fanfictions off the top of my head. But you could also check out fanfiction.net. Sometimes, fan communities on platforms like Reddit might also recommend good ones if you post a request there.
One emotional moment could be when Kono is injured during a mission and her friends fear for her life. They gather around her in the hospital, and the worry on their faces shows how much she means to them.
Five's injury can slow down the action. If he's hurt, he can't use his powers as effectively, which might make the group more vulnerable. So the plot then focuses on protecting him and finding a way to heal him.
You can start by looking on Archive of Our Own (AO3). It has a vast collection of 'Umbrella Academy' fanfictions, including many focused on Five. The site has a great search function that allows you to filter by character, genre, and more.
There's also a fanfic called 'Five and the Mysterious Portal'. This one combines Five's ability to jump through time and space with a new, mysterious element that adds a whole new layer of intrigue to his story. It's full of action and unexpected twists that keep you hooked from start to finish.
I also like 'The Lost Years'. It fills in the gaps of the characters' lives that were not fully explored in the show. It's full of interesting backstories and character development.
There could be a fanfiction where Five and Vanya accidentally swap powers. Five suddenly finds himself with the power of soundwaves while Vanya can time - travel. This leads to a lot of chaos as they both struggle to control their new abilities and also have to deal with the implications it has on their relationships with the other Umbrella Academy members.
Another theme is his relationship with his family. His siblings may not fully understand his pain, and this can lead to situations where he gets hurt, either by their actions or inactions. His family's neglect or misunderstanding of his power - related issues can be a central part of the hurt in these stories.
The 'Umbrella Academy Five Returns Earlier' fanfiction might explore various aspects. It could focus on how Five's earlier return disrupts the existing timeline in the Umbrella Academy universe. Maybe it shows how the other characters react to his unexpected early arrival. For example, his siblings might be shocked and have to quickly adapt to his presence, which could lead to new alliances or conflicts within the group.