About Chrona, Medusa seems to be the mother, but did she really give birth to Chrona?
If so, did she need a father?
More generally I wonder how it works in Soul Eater's world. Maka's mom is human (but are Masters really humans?) and Maka's dad is a weapon, yet Maka is a human and not a weapon. So, how families of weapons can exist (Tsubaki's case)?
I'm not sure there is rational explanation for this.
We still have to see Maka's mom and her weapon that should be awesome.
I'm preoccuppied with another point. Death Scythes seem in charge of zones in the world. Do they have a partner? Maybe, there are many masters in the zones and when the times come, one of them take the death scythe to do the job.