Board Thread:General Discussion/@comment-10587310-20140627203641/@comment-5398287-20140627230246

Your theory MIGHT hold ground...except for one thing.

Driscoll Berci managed to use Choujirou's Bankai, Koko Gonryou Rikyuu, even after he killed Choujirou in combat.

So Yhwach can still use Zanka no Tachi despite having killed Yamamoto.