6. Sage Mode
Sage Mode is activated when one combines the nature’s energy with one’s chakra, and it enhances the abilities like speed, strength, etc. Some well-known users of Sage mode are Hashirama Senju, Jiraiya, Naruto, etc. Another kind of sage mode is Six Paths Senjutsu. Granting the user the abilities to use all five natures and yin and yang release. One can have this ability if he is a Ten Tails Jinchuuriki, or has been given Six Paths Chakra, like Asura Ōtsutsuki and Naruto Uzumaki. Sage Mode is a drastic boost, so it is considered very OP.
5. Edo Tensei
It is a technique which can bring dead back to life. It was invented by Tobirama Senju, the second Hokage. Its power was fully demonstrated by Kabuto Yakushi. During the Fourth Great Ninja War, he reincarnated many Legendary Shinobi like Madara, Nagato, various Kage and Kinkaku and Ginkaku. It changed the tide of the war for sometime in Akatsuki’s favor. These shinobi are completely indestructible, and they have infinite chakra reserves. Even if they caster is killed, the Jutsu won’t be undone.