Vampirism

If, on your adventures, you are so (un)lucky to encounter a vampire, likely a battle will follow. Either by your own curiosity or because the vampire noticed your presence and charges at you.

Beware that they are tough opponents.

In battle, it is possible that you drop your guard for a moment and that the vampire manages to infect you with xyz. That, on its own isn't as horrendous as it may sound but it leaves you with a choice. Either get it cured, or embrace the life of a vampire.