Hemalurgy can be used to steal Allomantic or Feruchemical powers and give them to another person. However, a Hemalurgic spike can also be created by killing a normal person, one who is neither an Allomancer nor a Feruchemist. In that case, the spike instead steals the very power of Preservation existing within the soul of the people. (The power that, in fact, gives all people sentience.)
