Because elves change when they return to Aman. They change thoroughly.

On topic, Lalaith wasn't a biter. Someone else was. If you want to know who, pay attention.

This person participated in Nirnaeth. He was a mortal Man. It wasn't Hurin or Huor or Uldor or Ulfang or Ulfast or Ulwarth. He was mysterious biter.

That's right. That biter is someone familiar to Morwen. If you want to know who, ask my aunt Aerin.

Urwen.

Deceased