1. Six Paths Madara: Madara Uchiha became the first Jinchuriki of the Ten-Tails during the Fourth Great Ninja War. He possessed the Rinnegan and was considered stronger than Hashirama Senju, the First Hokage.

2. Six Paths Obito: Obito Uchiha also became a Jinchuriki of the Ten-Tails during the war. With his two Sharingan and the awakened Rinnegan, Obito's power surpassed even the First Hokage's.

3. Six Paths Naruto: Naruto, a reincarnation of Asura, gained an even more powerful form after having the Tailed Beasts extracted from him.

With the assistance of the Fourth Hokage, Sasuke, and Hagoromo, Naruto's power surpassed that of the First Hokage.

4. Six Paths Sasuke: Sasuke awakened the Nine-Tomoe Rinnegan with Hagoromo's help. His Rinnegan is stronger than Madara's and can be seen through Madara's Limbo. Sasuke's Rinnegan is also immune to ninjutsu and is unmatched by Hashirama's Advanced Sealing Jutsu.

5. Kushina Uzumaki: Kushina was the first Jinchuriki of the Nine-Tails and the wife of the First Hokage. Due to her hot-tempered nature, Hashirama would have been somewhat afraid of her.