Questions about Talisman Abundance Hunter

hi, about this talisman during pvp when i do 1frag a buff hunter talisman appear in my buff bar, this buff give same things than the talisman but with low power.(1% at lvl1). However each time i kill ppl, the buff grow up, at lvl5 it give 7% to stats ( instead of 15% in description). so iam confused about the effect of talisman, in my mind the effect is apply when wearring this talisman and confirmed by passiv item skill, but the buff from killing ppl is added to the effect of talisman or the talisman do effect only when you kill ppl?????