Vampires are people too.
We live in the dark and prance around in the sunlight.
No, really.
That or we're just bored.
Or crazy.
Both, most likely.
Regarding the joining the guild concept:
This is a very small guild which never recruits.
Translation: Exclusive private party by invitation only. As the Japanese say, "So sorry."
It should be noted that the guild leader is a first-timer, unconventional, and probably doesn't know the first thing about playing this game. xD
"When other little girls wanted to be ballet dancers I kind of wanted to be a vampire."
~ Angelina Jolie