Found out what I was doing wrong. Seems the #secondarypath command might be a bit bugged. It sometimes overwrote the #mainpath command. All that was needed was to put #constlevel 8 for each superunique. Got my prophet decked out in Solaris Sun Set now.
Noticed that it's just not death9 blessing that creates the same soulless every time. All the soulless summoned by the "Raise Dead" seems to be this one unit as well. I'm starting to suspect there's very simple explanation behind this error. :/