I'm not really sure specifically about 'ppgz y rrbz vampiros fanfiction' as it seems quite a niche combination. But you could start by looking on popular fanfiction platforms like Archive of Our Own or FanFiction.net. Try searching for the key words and see what pops up.
You can try looking on Wattpad. It has a wide range of fanfictions, and there's a chance you'll find something related to 'ppgz y rrbz vampiros' there.
Some of the popular ones include 'Solo Leveling' and 'The Beginning After the End'. They have gained a huge fan following for their unique storylines and characters.