It could be a jealous rival. Maybe someone who is envious of Peter's success or his relationship with a certain person.
A deranged person who has a grudge against Peter for no real logical reason could be the shooter. This person might have seen Peter in passing and for some reason developed an irrational hatred towards him. Or it could be a hired gun, paid by someone who has a more calculated reason for wanting Peter out of the way, like in a business or power struggle.
It could be a new villain, someone who has a personal vendetta against Peter Parker. Maybe a criminal whose operations Spider - Man has disrupted one too many times.
In this kind of fanfiction, one scenario could be that Peter is in a dark alley and gets shot by a mysterious assailant. Then his friends or family members might start a search for the shooter. Another possibility is that Peter is shot during a conflict between two groups, like a gang war that he accidentally gets involved in.
It could be an ex - boyfriend who was jealous and wanted revenge. Maybe he couldn't handle the break - up and decided to harm her in this extreme way.
There's also a possibility that it's an agent of a secret organization. This organization might be aiming to disrupt the hero society, and they see Bakugou as a key figure to target. So they send one of their best shooters to take him down.
It could be an ex - boyfriend who is jealous of Annie's new relationships. Maybe he couldn't handle seeing her move on.
It could be an old enemy of Chuck's. Maybe someone from his past who has a vendetta against him for something he did before.
A possible suspect could be an informant who has turned on Tony. Maybe the informant was promised a better deal by another party if they got rid of Tony. Also, it could be a new criminal on the scene who sees Tony as a threat. This new criminal might be trying to establish their power and reputation, and taking out a well - known NCIS agent like Tony would be a big statement. Another suspect could be a person with a grudge against the NCIS in general, and Tony just happens to be an easy target.
Perhaps Peter has to keep his identity a secret even while being treated for the gunshot wound. This could lead to some tense moments in the hospital as he tries to avoid giving away who he really is. Also, the villain who shot him might come back to finish the job, creating a high - stakes situation where Peter has to use his wits more than his strength in his weakened state.
One possible plot could be that the house is a sentient being in a magical world. A dark sorcerer wants to take over the land where the house stands. When the house tries to protect itself, the sorcerer shoots magic bolts at it. The inhabitants of the house, who are fairies, then have to find a way to heal the house and drive the sorcerer away.
It could be a dark wizard who has a vendetta against Fairy Tail. Maybe someone who Natsu defeated in the past and is now seeking revenge.