Buso Renkin
During the "Dead Body and Lover" story arc in the serialization, the last half of this one-shot, beginning with John Doe battling Lord Cadaver's Frankensteins, was re-published and labeled as a "special sideline story". It was also combined into the first volume of the series, suggesting that it is part of the canon. Prior to that it was added to the last volume of Watsuki's previous series "Buso Renkin", and Viz Media retained it there for their English translation of the series.