Terms for subject Informal containing its own

English	Russian
on its own	само собой (Andrey Truhachev)
on its own	сама по себе (Andrey Truhachev)
on its own	само по себе (Andrey Truhachev)
was in a league of its own	быть чем-то из ряда вон выходящим (DoctorKto)