Who is Ghadheal al-Fali from Children of Dune and what is their importance?

Ghadheal al-Fali is a desert-born Fremen Naib, and one of Muad'Dib's death commandos. al-Fali attends one of Alia's morning audiences on "a matter of the desert" - to express his concern about losing the desert. He then kills a Priest who tries to assassinate Jessica and follows her out of the Chamber along with four fellow Fedaykin.