Yes we need more information on these items but please explain the part I highlighted.what makes me wonder is , oro wanted that sword yet kabuto made no attempt to get from itachi when he was under his control.
Kishi for some reason has given these legendary weapons and itachi plot armor, high levels too. Rivals that of sasuke.
Kishi hasnt even told us how itachi got them and more importantly why itachi got them and not some other character like tobi and madara who seem to know wabout all hax things in the world.
Explanation is Simple. Kishi is Itach fanboy LOLYes we need more information on these items but please explain the part I highlighted.
Sasuke has no legendary items last I checked.
Kin-Jin duo and the Raikaga are the only other characters to have shown other legendary items.
So yes, we need to know how Itachi got them but it's pretty clear as to why he got them. Who wouldn't want Yata's Mirror and Blade of Totsuka in their possession? Maybe Kishi should explain how the Kin-Jin duo got their items as well.