Dealing with a situation like this can be difficult, especially for individuals who may not have a lot of experience with social media platforms. If you believe that an account is being unfairly targeted with mass reporting, one option is to report the issue to Twitter's support team. They may be able to investigate the situation and take appropriate action.
Another option is to encourage the targeted user to reach out to Twitter's support team themselves. They may be able to provide more information about the situation and help to resolve the issue.
It's also important to remember that engaging in mass reporting or other forms of harassment is not acceptable behavior on social media platforms. If you see this kind of behavior happening, it's important to speak out against it and report it to the appropriate authorities.