A lot of people ask the question "Can I become a vampyre" Well it depends on who you ask.
Vampyres are not like fictional vampires. Fictional vampires have "super powers" While vampyres are for the most part regular people. The only difference is they feed on life force.
Many people feed on life force for various reasons some do it because they feel as though they need it others do it because it is a spiritual path and practice for them
What are the benefits?
In the psychic vampyre codex by Michelle Belanger she talks about psychic links that you make when you feed on someone's energy. You can pull someone to you by making them think of you through these links you can also harm someone if you wish through these links, these are called or considered energy links.
Also Michelle Belanger talks about vampyres being stronger and having stronger senses(She doesn't mean anything supernatural, a vampyre might be stronger than normal but regular people can be stronger and have better senses without being a vampyre)
Is this a religion
Well it depends on who you ask.
Can vampyres fly, shapeshift etc?
Through astral projection but so can anyone
Are vampyres immortal.
Not physically. Some vampyres do believe in a special type of spiritual immortality.