Everything

By turning the force of cosmic entropy against an entity, a Master of that Sphere can disrupt the concept behind a spirit’s existence. In this case, the wracking demands Entropy 5 (the Rank that degrades ideas) and Spirit 5 (the Rank that allows a mage to reshape ephemera). In addition to the usual damage inflicted by the attack, the mage could scatter the spirit’s conceptual foundation… usually for a while, possibly forever.

In most cases, a spirit can reform its conceptual essence of self in a few months. A really minor spirit – that is, one with 10 Essence or less – doesn’t contain enough “sense of self” to reform at all. A truly potent entity, however, may reform its concept of self much faster… possibly, if you’re talking about an entity with a powerful hold upon the human imagination (Cupid, Pan, Cthulhu), within minutes, thanks to the force of that belief.

Minor entities (servitors, elementals, etc.) may be scattered when their Essence Trait reaches 0. A powerful entity may require two or three times its Essence Trait before its conceptual self gets dispersed; an aspect of the totem-spirit Owl, for example, could have 40 Essence and require the equivalent of 80 health levels worth of damage before its conceptual self is dispelled! Meanwhile, a spirit who occupies a prominent place in the human imagination probably cannot be dispelled at all… or not for any length of time, at least. Sure, a powerful magus could probably disrupt the concept of, say, the minor demon Moliax; dispelling the concept of Satan, however, is just not possible.

(Any mage stupid enough to try using Entropic dispersal against a wraith would deserve the spectre-inflicted beating she’d receive; see the note Entropy Does Bad Things to Ghosts