I'm reading the Children of Hûrin and look what i just saw there...
" and in a grim mood he (Turin) found in the armouries a dwarf-mask all gilded, and he put it on before battle, and his enemies fled before his face. ."
So as far as i understand he found a mask with a dwarven face on it, that mask was so ugly... wait... that dwarves face was so ugly that all enemies fled. Fuck it, Dwarves are ugly, here you got your proof.