Most types of weapons mentioned below have proven to be quite ineffective when utilized in real life. Additionally, many people tend to use these weapons in ways that can potentially harm themselves more than they can achieve their intended goals. Below are some such weapons:
7. Tensa Zangetsu of Ichigo Kurosaki – Bleach

It can be said that the Zanpakutō from Bleach holds a significant place on this list. In its original state, Ichigo’s katana is quite long and can indeed cause substantial damage. However, when Ichigo’s Bankai is released, the katana becomes incredibly heavy.
In practical terms, this Shinigami sword is imbued with a strong spiritual presence, making its considerable size impractical for real-life use. Even according to Shinigami standards, carrying Tensa Zangetsu would be a burden rather than a useful tool, let alone hitting a target effectively.
6. Yoru of Dracule Mihawk – One Piece

Considered one of the most powerful swords introduced in One Piece, Yoru resembles a traditional Kriegsmesser, with a blade that is extraordinarily long and heavy.
In real-life scenarios, Mihawk’s sword would be unwieldy and could significantly affect the wielder’s ability to defend themselves during combat.
5. Kubikiribōchō of Momochi Zabuza – Naruto

Every sword in the Mist Village of Naruto is supposed to possess a powerful unique ability. Kubikiribōchō of Momochi Zabuza is a massive sword shaped like a cleaver, allowing its wielder to utilize the circular notches on its blade to decapitate enemies. This sword cannot be dulled or broken due to its regenerative properties, as it can absorb the blood of those it slays to repair itself, making it nearly indestructible.
Despite its unique qualities, the practicality of this weapon is questionable, particularly because of its considerable size.
4. Blazing Sword of Voltron – Beast King Go-Lion

The effectiveness of the Blazing Sword is not the main point of contention within a world that includes Transformers, Jaegers, and other giant robots. However, it is worth noting that without Voltron or any large robots, one would find it difficult to wield the Blazing Sword effectively.
3. Samehada of Kisame Hoshigaki – Naruto

Samehada is a sword covered in scales, equipped with numerous spikes along its length. Unlike other weapons, it functions as a “living” tool that, when near an opponent, can absorb their chakra and feed it back to the user, thus restoring energy and power.
However, this unique characteristic can also pose significant challenges for the wielder, as the sword’s unwieldy size makes it difficult to handle effectively in combat.
2. Death Note of Light Yagami – Death Note

Does the Death Note have any practical use in reality? Certainly, unless one merely wishes to write down information without the expectation of anyone dying immediately as in the series. The potential of the Death Note is to turn its user into a god among humans.
In theory, one could follow in Light’s footsteps and generate a list of individuals targeted for elimination. However, the ethical implications of such a tool could lead to severe consequences, turning the user into a criminal while having to hide from law enforcement.
1. Bustermarm of Panther Lily – Fairy Tail

Bustermarm is an extremely large and unique sword. Its size is roughly the same as that of its wielder. The blade is thick and has two edges, with its cutting capabilities being far superior compared to its size. This magical sword can cut through an entire planet. Bustermarm can also change its size, similar to the Sword of Musica that Panther Lily wields in Tenrou.
For an average person, lifting Bustermarm is unlikely to be successful. Even if it is made of the lightest materials, its sheer size would make maneuvering it extremely difficult.