Give me the understanding I need

So I am on my first playthrough of DS2 and I was interested in doing a crypt blacksword build. I just found out that you can't get the weapon in your first playthrough and that it is only attainable in NG+. Even if I burn an ascetic, it is not available to me until I get to NG. Am I understanding this correctly? Because I'll need to go burn a soul vessel to change my character up altogether if so.

edit: I am only at the Ruin Sentinels, so not far but enough where I will probably change my build up in a new direction altogether