[quote=Walker of Darkness]
Huh, I counted 34(unique souls, at least) in the CE Guide. Maybe it does count mini bosses.
[/quote]

I think this is what's giving you the count:

[hider=Spoilers]To kill the optional boss King Vendrick, you have to accrue four Giant Souls. Each of these is a unique soul, so to speak, but all have the same title. "Giant Soul" Add these four to the 30 bosses and you get 34 unique souls.[/hider]