[quote=Imperfectionist]
But, as I said, he was always more dangerous (it seemed) when he being autonomous.Also, has anyone else wondered how Justin Law fought before he became a Death Scythe? It would have been pretty difficult...EDIT: He generated his chain without giving up any body parts... Ergo, Death Scythe, or something similar.
[/quote]

in the manga it is largely implied that Humans and weapons of great spiritual power and training can be plenty powerful and self reliant. This is demonstrated possible for both humans and weapons ( Mifune being literally having the strength of 99 souls in the manga and Giriko's own soul become so powerful and full of hate that it collapses on itself )

So theoretically Justin Law always had the proper amount of soul wave length to be a solo fighter and made himself a death scythe. Much like how Black star can preform attacks that do damage on a soul level because of how powerful his own is. But these kind of characters are 1 in a million, literally only having the three I've mentioned ( 4 if you include Stine and how powerful he is with out a weapon as well )

It is why my whip girl failed as a solo weapon, she has an average soul wave length so while she has the technical skill she can't make up for her lack of power with out a partner.

But that is pulling a bit more from the manga than it is the show, so take all that as you will.