The 4th Great Ninja War was jam-packed with many strong reanimated shinobi from older generations. They were reanimated by either Kabuto Yakushi, or by Orochimaru. This set the 4th Great Ninja War apart from all other wars .
Here are the 10 strongest Ninja who were reanimated during the 4th Great Ninja War.
Mū was the Second Tsuchikage of Iwa. He wielded the Kekkei Tōta of the Dust Release. Mū was also the teacher of Onoki. Being reanimated by Kabuto, he also avoided being sealed and was the one to summon Madara Uchiha to the battlefield.
Hanzo was a very powerful shinobi. He was also the leader of Amegakure. Hanzo was so powerful that he defeated the Sannin easily. Later, his skills waned because he changed his beliefs. His deadly skills led Kabuto Yakushi to reanimate him during the 4th Great Ninja War.