!! Last time Orochimaru face Itachi He lost a Hand to Itachi.
He is talking about Orochimaru's chakra that was sealed inside the Totsuka Sword.
indeed; thank-you both.hm, so it is believed he would receive a chakra boost then... HmI think he means the part of Oro sealed inside Sword of Totsuka during Sasuke vs Itachi when Sasuke literally had no more chakra to suppress it.
OT: Yes, I would think so, assuming he finds a way to break the seal. Then he'd just have to re-edo Itachi.