A brief description of the “The Labyrinth Raids Of The Ultimate Tank ~The Tank Possessing A Rare 9,999 Endurance Skill Was Expelled From The Hero Party~” manga:
One day the Hero considered Rude, the strongest tank in the world, useless. After all, Rude could only defend himself, but not attack. Hero threw Rude out of his group. Then Rud’s admired Rud Hiller and Rude himself, without much choice, went to a remote village.