But imagine that a friendly neighborhood vampire starts attending an Orthodox synagogue and expresses a desire to convert to Judaism. Of course, the Rabbi only wants to accept converts with a serious commitment to Torah, which raises the question: Would any of the 613 Commandments be particularly difficult for a vampire to keep, because of being a vampire?
The most obvious one is the prohibition against consuming blood (Vayikra/Leviticus 7:26). But suppose that an acceptable kosher blood substitute could be produced. What other halachic issues could potentially get in the way of a vampire becoming an observant Jew?
For the purpose of this question, it shall be assumed that vampires have the following traits:
- Extremely delayed aging, and typical lifespans of 500 years or more. (But not literal immortality, since one could be killed by a stake through the heart or similar severe trauma.)
- Ability to shapeshift between human and bat form at will.
- Ability to fly, at least while in bat form.
- Allergy to garlic.
- Extreme susceptibility to sunburn. Exposure to direct sunlight, while not necessarily instantly fatal, is at least very painful.
- Lack of reflection in mirrors.
- Strong aversion to crosses and crucifixes. (Surely not a problem!)