In fanfiction, his scars could be a result of self - sacrifice. Suppose Ezra was protecting his friends from an explosion. He threw himself in front of them, and the debris from the blast hit him, causing the scars. This would show his loyalty and heroism within the Star Wars Rebels universe.
Maybe Ezra got his scars while exploring a dangerous and uncharted planet. He could have come across some fierce native creatures. For example, a large predator might have attacked him, and in the struggle to fend it off, he got scratched up badly enough to leave scars. These scars would then symbolize his adventurous and sometimes reckless nature.
One possibility could be that they are from a lightsaber duel with an Inquisitor. During a battle for survival, the Inquisitor's blade grazed Ezra, leaving the scars as a permanent reminder of the encounter.
In a fanfiction, Ezra's scars could be magically enhanced. Maybe he discovers an ancient Jedi power that is awakened by his scars. This power gives him unique abilities that he uses to fight against the Empire. For example, the scars could glow and act as a power amplifier for his Force powers, allowing him to perform feats he couldn't before.
Another idea is that Ezra's scars are a connection to a parallel dimension or a different timeline. Whenever he uses the Force in a certain way, his scars start to tingle or glow, and he has brief glimpses into this other reality. He then has to figure out if this is a warning, a chance to change something, or a new power source for the Rebellion.
In Star Wars Rebels fanfiction, Ezra's potential girlfriends often vary. Some fanfictions might pair him with Sabine. Their relationship in the show has a lot of chemistry that fanfic writers like to explore further. They share many adventures together, and this bond can be developed into a romantic relationship in fan - made stories.
The scars might make Ezra more cautious. After getting them, he realizes the real dangers in the galaxy and becomes more careful in his actions, especially when facing the Empire.
Perhaps in the fanfiction, the Empire discovers a connection between Ezra and Revan and tries to use it against them. They create a false prophecy that says Ezra will become like Revan and bring destruction. Ezra has to prove that he is different and that he will use Revan's story as a guide to bring peace and justice, not chaos.
He could be kidnapped by a group of pirates who mistake him for someone else. These pirates are known for their ruthlessness. The rebels would need to negotiate with other pirate groups to get information about Ezra's whereabouts. It would be a story full of danger and unexpected alliances.
The plot could be that Ezra loses his lightsaber in a skirmish with the Empire. He then embarks on a dangerous mission to retrieve it from an Imperial stronghold. Along the way, he teams up with some unlikely allies who help him infiltrate the base and get his lightsaber back.
Meeting a powerful dark side entity that can manipulate their minds. This entity could make them see their worst nightmares as if they were real. For Kanan, it might be the fall of all his friends and the destruction of the Rebellion. For Ezra, it could be the death of his family all over again. They have to fight against this mental intrusion and their own fear.
One possible plot could be Ezra being lured to the dark side by a mysterious Sith artifact. He starts to have visions of power and control that the Sith offer. As he delves deeper, he begins to distance himself from his friends in the Rebels, causing conflict within the group.
Ezra could be tortured for information about the Rebellion. The Empire would be eager to know Rebel plans and bases. His capture might also lead to the discovery of some of the Rebels' secrets if he accidentally reveals something under duress.