1. Thunder God Sword: It was shattered by Naruto and Sasuke's Rasengan and Chidori and never displayed its supposedly incredible power. 

2. White Fang Dagger: This dagger ended up in Kakashi's hands but didn't live up to its reputation. During the fight with Kaguya, Kakashi broke the White Fang Dagger, rendering it useless. 

3. Decapitating Carving Knife: Among the seven legendary ninja swords, this one is the weakest. As it doesn't provide any significant advantage.

4. Seven Star Sword:Essentially, the Seven Star Sword is just an ordinary weapon, comparable to scrap metal.

5. Heavenly Swamp Spear: Obtained by Madara after becoming the Ten-Tails Jinchuriki during the Fourth Great Ninja War, this legendary weapon was shattered by Naruto and Sasuke's combined efforts.