Nagato and Itachi are both dead... Maybe you meant alive at the start of shippuden? If that's the case:
Itachi and current Sasuke
Nagato and Jiraiya
Kakashi and Gai
Sasori and Gaara
Orochimaru and Kisame
It's called kamui, not "kumai" or "kumi" or "kami." I don't know if half of NB is dyslexic or just plain dumb, but seriously. It's a 5 letter, commonly seen attack. Learn to English, guys.
Edit:
Fair point. Learn to type/read.