this is interesting to me lol the buffy-verse vamps seem to me to be below the marvel versions, but buffy is considerably above the vamps in her universe. she has some cool feats, but hard to say how they scale. i think i'd take blade, but if this happened in a comic, i guarantee it would end in a draw. not sure. beyond a few comics and the tv series i don't know buffy all that well. i'd love for someone to make a better case for her.
It depends which comic versions of Buffy were using. The last comic I ever read, this higher being named Twilight needed to be born in our universe, so it chooses Angel and Buffy to be it’s parents. As Twilights parents, they were offered many gifts.
-Flight
-Invulnerability
-Super speed
-Angel and Buffy having sex was raised the temp and caused quakes through
-Having sex, they give birth to Twilight, the being and the universe
- in said Universe they are literal gods, they can create anything with just a thought