[@Dark Light] sun stones do emit light, but it's not really sunlight ^^ Thus what makes vampires so dangerous. Also don't worry If delta keeps the vampire thing secret for as long as possible, once they are out into the tunnels your char will have no choice but to either roll with it, or attempt to return. Beside with a group as big as theirs, they can.. relatevely cosider traveling with vamp safe... 

 Also ohhh yeah not all bitten turn into vampires. Otherwise this will be overrun with vamps all the time. I will later add some more lore about vampires and werewolves in the OOC for this occasion. But consider you all that being bitten doesnt automatically turn you into a vampire.