From Neocron Classic Wiki
Heff is an NPC who is a member of Twilight Guardian. He lives in the Canyon Facility and hangs out near the fight arena.
He is part of the Twilight Guardian Epic and he also gives out supplies of <itemdb:link items="1755"/> grenades to runners who are a member of the Twilight Guardian faction and have completed the Twilight Guardian Epic.
Twilight Guardian Canyon