Where can I get the splitter of skulls (Lords of the Fallen)

http://ru.lordsofthefallen.wikia.com/wiki/%D0%A0%D0%B0%D1%81%D1%81%D0%B5%D0%BA%D0%B0%D1%82%D0%B5%D0%BB%D1%8C_%D1%87%D0%B5%D1%80%D0%B5%D0%BF%D0%BE%D0%B2

PLEXURA
(He falls with a certain chance when killing people armed with that weapon.) ! From what people??????????