In-Story Intros

One of the challenges with each Creeps book is to offer up a formal in-story introduction for each of the main characters to the reader that gives them a sense of their abilities/personality as it'll affect the story.
While on serialized comics, I can appreciate the need/efficiency of having an intro page on the inside cover and a "previously" synopsis to catch the reader up, I feel like books that might be picked up by kids out of order ought to make an attempt to give the kid a full stand-alone reading experience, and not make them feel like they bargain-binned some sequel.
The purpose of these on-page is probably painfully obvious, but I reckon that if I can make the context different each go 'round then it's okay, and it'll always serve new readers.