[quote=@TheUnknowable]
Could Unvaris be creating them as some sort of apocalypse plot?  The idea would be to return the worst psychopaths to the mortal world, spread them out, and then when you are ready, activate hundreds of sleeper agents to cause chaos, death, and suffering.  The death part of it could even be the result of Yishreenok being part of the plan and letting him have the souls in the first place.
[/quote]

I'd say if you wanna do that lests leave Yishreenok out that seems more of Unvaris style, especially if Thotafus might be envolved since they are members of the Dark six