How to get cursed katana?

Excuse me, could you please elaborate on how one might acquire a cursed katana? I'm quite intrigued by the idea, but I'm not entirely sure what steps I should take or where to even begin looking for such a unique and potentially dangerous weapon. Are there any specific rituals, quests, or dealers that specialize in such items? Additionally, what are the potential consequences of wielding a cursed katana, and how might one go about reversing or lifting the curse, if necessary? Thank you for your time and assistance.