Bruno

Bruno is a Fighting-type specialist. He is the second member of the Kanto Elite Four and the third member of the Johto Elite Four.

As Kanto Elite Four Member
Water types should be of help in this gym, as will Ghost types, as Fighting type moves don't affect Ghost types. A ground type should also help. Fairy or psychic types should also be useful. Just don't use a water type against Hitmonchan. 2 Water types, a Ghost type, a psychic/fairy type, and a couple of ground types at lvl 50-60 should crush Bruno.