A cast, not a new stranger every time
Children notice when a character changes. Make somebody once and they stay themselves.
A character in Taleium is four things: a name, what they look like, what they are like, and who they are in the story. You write those once.
They stay the same
Whenever a character is in a story, everything you wrote about them is put in front of the writing, every chapter. So the fox who was brave about everything except the dark is still brave about everything except the dark forty chapters later, and still has the battered hat.
They are drawn once
When you make a character, a portrait is drawn from what you said they look like. It takes a few seconds and happens in the background, so you are not waiting for it. That portrait then appears beside every chapter they are in, including on a story you have shared with somebody who has no account.
Change what they look like and the portrait is drawn again. Change only their temperament and it is not, because you liked that picture.
They cross between books
The cast belongs to your family rather than to a story, so the same character can be the hero of one book and a passing mention in the next. Tick who is in a story when you start it, or change the cast later from the story's own page.