Whether it's because the cost of using them is so great, or because the attack is just too epic to be used repeatedly, some anime moves only see the light of day one time. Let's take some time to appreciate some of the greatest anime attacks that were only used once.
One particularly disturbing example is the Tree of Depravity, a tree that Kurama summons from Hell in Yu Yu Hakusho. This tree forces the immortal Elder Toguro to hallucinate that he's fighting Kurama for the rest of eternity while it feeds on his life force. More recently, there's the United States of Smash, All Might's finishing move against All For One in My Hero Academia.
Which of these dramatic attacks impressed you? Be sure to vote them up.
Might Guy isn't the only person to open all Eight Gates, but he only does it once, and he's one of the only people to survive it. The Eight Gates are a series of blocks that prevent a person from using the full extent of their power. Removing each gate grants greater levels of strength, but it also damages the body. The Eighth gate allows the user access to a forbidden Taijutsu technique called Night Guy, but it also typically results in the person being fully destroyed.
Might Guy opens the Eighth Gate only once, during a climactic battle against Madara. He survives thanks to Naruto's Yin–Yang Release, but his leg is permanently damaged. As a result, he starts using a wheelchair.
After using a technique called Saigo no Getsuga Tenshō, Ichigo Kurosaki is able to achieve a form called Getsuga that dramatically changes both his appearance and his strength. Once in this form, he's able to use Mugetsu. Mugetsu lets him generate a huge black blade of Reiatsu energy that severely damages everything unlucky enough to enter its path.
Using Mugetsu means the loss of Ichigo's Shinigami powers, so it's a huge gamble. Luckily, he managed to land a hit that forced Aizen to revert to a previous evolutionary stage, making it possible to defeat him.
Indra's Arrow, a technique named for one of Sasuke's ancestors, is the ninja's strongest attack, period. By absorbing chakra from all nine tailed beasts and combining them in a vessel made from Complete Body — Susanoo, Sasuke creates a spectral bow and arrow that he uses to launch at his opponent: his best friend and greatest rival, Naruto Uzumaki.
Despite the intense power of Indra's Arrow, it's actually not Sasuke's finishing move in his final fight against Naruto. Rather, it's Chidori, one of the first moves he ever learned.
United States of Smash is All Might's most powerful technique. It's not that different from his other attacks - it's a powerful punch with a ton of energy behind it - but the energy levels are on another planet. He managed to grind his nemesis All For One into the dirt with it, despite the fact that his quirk had been mostly transferred to Izuku and his severe injuries made it difficult for him to fight at all. This would be All Might's last fight, and it was one of his most epic.
This isn't really the first time All Might used the attack, but it's the only time viewers get to see its full glory. Too bad, because it was probably ten times more amazing when the man was at his peak. It's also possible that this won't be the last time we see United States of Smash, either. While All Might's powers were extinguished, Izuku still has a lot to learn about the complex quirk he inherited.