Anyone here think Oda will explain the Shimotsuki plotline further ? He hinted at Zoro's lineage in an SBS while implying he'd share more details about it later
So i'm assuming that it'd be involved into the serie at one point, and judging by how far into the battle they already are with Kaido, it could probably only happen during or after the battle
There is also the nidai kitetsu plot to think about. This sword was introduced for a reason, with Zoro already showing interest in it, in at least 2 occasions
Since it's a superior curse blade to Sandai, that Enma already has a plot(turning into a black blade), and how special Wado Ichimonji is(Kuina's blade), i think it's safe to assume that nidai will be Zoro's new blade in replacement to sandai