Orochimaru is one of the three Legendary Sannin of Konohagakure. In the quest for immortality, he has killed a lot of people just for the sake of his experiments. His ambition is to learn all jutsu and to achieve this he keeps on changing host bodies to prolong his life. Even though we haven’t seen his full power, we have seen that killing him in battle in very hard. He even knows forbidden jutsu. To be alive and as young as ever only means that he’s stronger than before. Orochimaru is a legend without a doubt.
4. Tsunade Senju
Tsunade Senju is also one of the Three Legendary Sannin of Konohagakure. She is the Fifth Hokage of Konohagakure. Tsunade Senju is known for her healing abilities and her enormous strength. She has saved countless lives during the Shinobi Wars, and during the invasion of pain in Konohagakure. After the 4th Great Ninja War, she passed her Hokage status to Kakashi Hatake.