Defense Devil

Authors: Yoon, In-Wan (Story), Yang, Kyung-il (Art)

Publisher: Shogakukan, 2009

Online reading: https://m.manganelo.com/manga-ob89495

Annotation:

Mephisto Bart Kucabara is a devil that has been exiled from hell. In order to return to the demon world he needs to collect enough Dark Matter. To do so he play the part of lawyer for the dead soul to claim the Dark Matter from the souls of sinners sentenced to hell. When he prove the soul's innocence then he take half of the Dark Matter from the soul, and the sinner is free from hell. But how can he gather enough Dark Matter when his kind personality causes him to continually use it up in order to defend the soul from the Shinigami that has come to take them to hell?

For more information:

https://myanimelist.net/manga/13748/Defense_Devil
https://defensedevil.fandom.com/wiki/Defense_Devil_Wiki 
https://defensedevil.fandom.com/wiki/Defense_Devil_(manga)