Tsuihou sareta Fuguushoku "Tamer" desu ga, Futatsume no Shokugyou ga Bannoushoku "Haigou Jutsushi" Datta node Ore dake no Saikyou Party wo Tsukurimasu

Arga is kicked out of his party simply for having the “useless” job of Tamer. Taking the opportunity to reassess himself at the Adventurer’s Guild, he discovers a shocking truth. He possesses a Second Job, a phenomenon that occurs only once in a thousand years. His first job is Tamer, allowing him to befriend monsters. His second is Fusionist, a class that empowers him to combine monsters to create even stronger ones. With these two powerful jobs, Arga begins forming the ultimate party, made up of mighty monsters, the world’s strongest female adventurers, and even vampire princesses!
Source: MU