What happens when a Kyriotate or Shedite uses Song of Possession on someone?
They get the benefits of both their resonance and the Song for the duration of the Song. After that, treat it as a normal resonance-based possession. This means that a Kyriotate/Shedite could have two chances to possess the same host. (Note that it allows Shedim to possess non-human hosts, but they’ll still be booted when the Song duration ends.