The strongest character in anime is Saitama from "One Punch Man." One Punch Man differs from most other fighting anime in that the protagonist is already the strongest person in the room, rather than aspiring to be so. He can endure any hit and destroy any foe with a single severe attack after three years of intense training. Saitama's strength comes at a price, however: he is completely void of morals or ethics, which makes him very difficult to relate to. However, his actions do show some signs of morality being implanted in him by Genosix, his ex-sponsor who made him fight for his life every time he got into a situation it wasn't possible to escape from. Genosix also gave him purpose: to protect everyone on Earth without question or regard for self-interest. This makes Saitama the perfect hero for our times: he knows what it means to have responsibility, and strives to be a good man who does good things. Also worth mentioning is that while Saitama is definitely the strongest character in the series, this doesn't mean he's the only strong character. For example, Sanada Bakuya was once able to defeat Saitama but was then defeated himself by Genosix. Also, during the final battle with Genosix, when everything seems lost, Morio Watanabe shows up and uses his power to help Saitama win.