explosion, war, trap
Oh that sux. Was it cuz of the necklace?
he just rushed into battle.... an set of a bomb
Orochimaru was his sensei back then, Nawaki thought he is overpowered and jumped right into enemie's trap ... boooom!
Huh? Where did u see orochimaru was his sensei?
I couldn't tell you where exactaly but I can say that Oro was his sensei. I remember the flashback clearly. Tsunade came running in and Jiraiya stopped her and the three (Orochimaru, Jiraiya, and Tsunade) were in a dark room and a bloody sheet (I'm pretty sure it was bloody) was placed over the dead body and Orochimaru said that if she looked at it she probably wouldn't even recognize the body the way it was and it was stated that he was blown up on the war front. That was when Tsunade proposed that every shinobi squad have a medic, to the council and that's when she met Dan who shared the same view. They fall in love and Dan is given the necklace of the first Hokage by Tsunade and later on in battle he was bloody and dying and Tsunade was trying to save him but she couldn't and that's when she was discharged from the war because she developed a fear of blood. I don't know if you needed all that just adding it on just in case.
rewatch manga and that episode and reak wiki ... it seems Oro was his sensei ... thats why he gone all crazy over immortality when he saw Nawaki boom and Dan's death
tsuande boobs crushed him.