Orochimaru and Third Hokage in “Unfinished Business”

Orochimaru

The immortality jutsu. A technique for eternally recycling one's spirit on Earth. In a way, it's a kind of revival jutsu. You find a body, a young body, pour your spirit into it, and make it your own. I was using my old familiar form until now because I wanted our reunion to be a nice nostalgic one, sensei. Growing old is a sad empty thing. I only have to look at you to be reminded of that. You will die here old man, while I move on to another stronger body. But first I really must thank you and all the Leaf Village for preparing my next body so well.

Now I understand. It's Sasuke Uchiha.

Orochimaru

Exactly. You guessed it. It's Sasuke I want.