Question regarding feather damage

So, on the bald eagle nest cam I watch (Decorah), for the past several days there's been this male Red Winged Blackbird that has been getting increasingly bold in his aggressive behavior towards the fledgling DH2 (~4mo).

At first it was just kinda funny because for the most part. DH2 ignores him, and the size difference makes it sort of comical. It was mostly dive-bombing pecking attacks, but starting yesterday, Mr. RWBB has been landing on DH2's back and repeatedly pecking their feathers, and no doubt causing damage to the feathers. So I was wondering how serious this type of damage is? I know that whenever I found a feather as a kid, once you separate the strands, they never go back to how they were. This no doubt will have an effect on flight, right? DH2 is too young to know what to do, and the parents don't seem interested in getting involved (although, tbh, I would not be surprised if mom delivers that pest to the nest as a meal someday soon!)

Thoughts? You can scroll back to several incidences in today's stream. Ask if you need me to find timestamps. Thanks in advance.