Invisible form

Invisible form is another form that a succubus can use. This form requires a small amount of lust energy to maintain.

Invisible form is not true invisibility. Instead, it works by emitting light waves and pheromones that tend to confuse most seeing creatures in such a way that the succubus becomes inconspicuous. The illusion fails, however, if someone is looking for the succubus or has "a sufficiently open mind" in a way that makes them more observant to detail (ie in the case of Spoons' first encounter with Euryale).