[Anh_Minh]

Spoiler for manga:

I think she meant the first weapons.

Nowadays, I think they're just born that way. Or you wouldn't find homeless weapons like the Thompson sisters.

Though I do wonder when what weapon they can turn into is decided. Tsubaki's backstory seems to say that at some point in their life, they're given pre-existing, non-demon weapons to fuse with. But is it only her, or did Soul eat a scythe as his tenth birthday cake, or what?