[Edi]

As a note, I think the charm spell also has the Enslave Mind attack effect, just that the spell sound effect is different because it is specified in a different place maybe? The Enslave Mind attack (that units may have) uses the astral spell default sound, and the nature spell charm uses the nature spell default sound, but it still has the same attack effect (it must, because all damaging spells with special effects must have something for the effect) because there are no others. Unless the spells have a Category of those all on their own, but I doubt it.

Edi