1. The Eight-Tails is the second strongest-tailed beast, showcasing its power in the anime when it fights against the human-Gedo army led by Tobi.

2. The Three-Tails is argued to be the weakest based on its limited abilities and lack of special powers. It was captured in its complete form by Deidara and only possesses a simple water chakra nature.

3. The One-Tail, Shukaku, is mentioned to have strong defense and sealing techniques. The Two-Tails, Matatabi, is highlighted for its blue flame powers and above-average strength.

4. The Four-Tails, Son Goku, possesses the lava release kekkei genkai and is considered to have moderate power.

5. The Five-Tails, Isobu, has average abilities with exceptional speed. The Six-Tails, Saiken, relies on its corrosive fluids for combat strength. The Seven-Tails, Chōmei, uses its scales and flight ability in battle.

6.If you want to say who is the weakest among the nine tailed beasts, it is probably the three-tailed Isobutsu. The three-tailed Isobutsu was captured by Deidara in a complete state, and he has no special abilities and only simple chakra. It has the water attribute, so there should be no suspense about its weakest strength.