The Judas Chalice is a fictional item. The stories describe Judas Chalice as an Unholy artifact made out 30 pieces of silver. According to those stories Judah, the betrayer of Jesus was a first vampire. He was cursed to never die. The Judas Chalice is the holy relic of vampires, which grants its hellish users an ability to heal rapidly and improves other attributes as well.
I do not know why Judas was later demonized. After all he was the treasurer of apostles who ran the first charity fund of the Church. Considering that the Temple money exchangers sometimes sold special coins (silver shekels) for 70 pieces of silver, the price of Jesus's betrayal is pretty low.
