Minus Skill Mochi Yonin ga Atsumattara, nanka Synergy Hakki shite Saikyou Party ga Dekita Ken

Minus Skill. A negative debuff possessed by a select few since birth. A swordsman who has one such skill is once again in the throes of being thrown out of another party. Despite his abilities, that single skill had a huge downside, which would make him a burden to any would-be adventuring partners. Sick and tired of the never-ending cycle, he has taken it upon himself to challenge a dungeon that may possess an item that could remove a skill of his. There, he meets a girl with the Priestess class who also has a Minus Skill but... "Eh? Aren't our skills synergistic? Negatives coming together to form a positive!" This is the story of people exiled from parties, who possess Minus Skills, banding together to eventually become the strongest party. (Source: Novel Updates)