[Baalz]

Meh, requires level 7 spell and it's not that powerful. You've got to have lots of priests, which means either you're not recruiting mages, you're using mages to generate freespawn, or you're putting temples up where there are no castles and getting weak indie priests. By the time level 7 spells are researched a couple hundred free undead is hardly earth shattering. I see this is being only very situationally useful and thematic. You could maybe use it for something interesting like cranking out a bunch of giant undead, but it's just one of the many, many interesting quirks you can exploit into a useful strategy.