In the 15 to 1 distillation protocol for H-type magic states, different protocols use magic states in different ways. In the original Bravyi-Kitaev paper, https://journals.aps.org/pra/abstract/10.1103/PhysRevA.71.022316 , the magic states are inputs into the circuit. In other papers such as this one: https://arxiv.org/abs/1208.0928 , the distillation circuit takes into noisy magic states as ancilla qubits to perform a transversal T gate (Fig 33). There is a post: Is it possible to perform magic