B. Feix (and D. Kaledin independently) showed that there exists a hyperkähler metric on a neighbourhood of the zero section of the cotangent bundle of any real-analytic Kahler manifold. B. Feix provided an explicit construction of its twistor space and showed that any hyperkahler manifold admitting a rotating circle action near its maximal fixed point set arises locally in this way. The construction have been further generalized to hypercomplex manifolds, quaternionic manifolds and quaternion-Kähler manifolds. In this talk we will discuss the cases of the construction. Then we will show how to apply it, to obtain a local classification result for quaternionic manifolds with rotating circle action near maximal fixed point set. Finally we will mention connections with c-map.