When exactly does Ayaka do that?

She does it against Lancer

Also means she was punching through protection from arrows

Do you mean the OVA? Or does Fragments of Sky Silver touch on the Second Tokyo War?

Because I've seen the OVA and read the script from Materials and nothing of the sort happens

Original Novel material

What novel?

Why isn't this on her page?!

That's why I'm asking, I've checked every source on her page and there is absolutely nothing supporting her feather bullets being even remotely close to that powerful.

Literally first few sentances of abilities. A servant with mag res doesnt have to guard against simple magecraft like that. Forcing a servant w/ mag res to guard as a modern magus is a big deal