One Punch Man
ワンパンマン (original)
The most powerful superhero in the world can kill anyone with one blow. But nothing can challenge him, so he struggles with ennui and depression.
Starring Kazuhiro Yamaji, Yuichi Nakamura, Kenjiro Tsuda, Aoi Yuki, Hiroki Yasumoto, Saori Hayami, Makoto Furukawa, Kaito Ishikawa, Hikaru Midorikawa
Watch "One Punch Man" on Crunchy Roll released in 2015. It's a animation and action & adventure show, and has a rating of 8.7 out of 10 from Imdb which is very high for this kind of show, and is currently available to watch for free.