User blog comment:Salubri/The Thousand-Year Blood War arc Plot Points/@comment-4207271-20131129113026/@comment-11051098-20131129210753

You mean his Zanpakutô originally belonged to Unohana, and he took it after he beat her in their very first fight?

She was the 11th Division captain at the time, and she already fought and killed a lot of opponents at the time. And Kenpachi already had his Zanpakutô when she first saw him, on top of a huge pile of corpses he had killed.