Board Thread:Questions and Answers/@comment-5551986-20130428001810/@comment-8986886-20130501085030

Skitzo1 wrote: The similarities between Ichigo's and Isshin's zanpakuto Engetsu and Zangetsu could be due to the fact that Isshin was using his shinigami powers to contain her hollow. So they may have passed onto Ichigo in some strange way. Quincy absorb Reishi/Reiatsu/Reiryoku stuff right? If thats the case, it would make sense that a foetus Ichigo "absorbed" Isshin's shinigami containing powers alongside the remaining "Hollow Reiatsu" used for hollowification left by White in Masaki. And he obviously gained Quincy powers via blood. This just became the philosophy corner, so I'll just throw one more aspect into the mix.

Since Ichigo "borrowed" Rukia's shinigami powers for quite some time; shouldn't he (as a Quincy) also have absorbed part of Rukia's Zanpakuto, Sode no Shirayuki?

Of course since his quincy powers were dorment at the time, I guess that would explain why he didn't absorb the powers of Sode no Shirayuki. :)