According to the guide it's 13 for beginner, 7 for standard and 5 for proud. The guide didn't really help with the portals and item collecting but a major help with the bosses and such. Maybe a guide for fighting Julius but hey, still good nonetheless.
I'm pretty sure the only Thing the guide wa good for was portals :/ look at the sihlouette of the dream eaters, compare those to the Portal Map section at the beginning section of each world (in the guide) and that will give you like 3 possible locations for the portal location. It's very helpful.