Dybbuk

Dimo mentions this particular phenomenon while meeting with the Jägergenerals. It is from Judaism and is a partial spirit or personality imposed on a victim for some reason, usually a poorly kept ward on the outer doors of one's domicile, thus allowing the dybbuk access to one's home and one's person.

In the Girl Genius Universe this phenomenon is real and is accomplished by using highly developed machinery for transferring a consciousness from one body to another. We do not know if this was accomplished by Lucrezia Mongfish alone, or whether The Other inspired her. It could be either.

The dybbuk seems to appear when an attempt to transfer a personality into a body without removing the resident mentality and psyche. This creates a pocket in the victim's mind wherein the dybbuk resides and slides out to take over the victim's body whenever it is strongly motivated by some external stimulus--temptation usually. The victim will be as reflective of the dybbuk's personality whenever it is in control.

There are three known dybbuks so far in this story. One is Lucrezia-in-Agatha. The other is Lucrezia-in-Zola. The third is Klaus-in-Gil.