\newcommand\scrumwitch{
	\thispagestyle{empty}
	\hbox{}
	\vfill
	\begin{center}
	\begin{minipage}{.7\textwidth}
	\centering
	In the beginning God created the heaven and the earth.
	And the earth was without form, and void;
	 and it was a static void, and it was private.
	And God said: \enquote{It is not good that the void should be private;
	 I will make it protected,
	 so it can be enjoyed by everyone, and no harm shall befall it.}

	[...]

	And God said: \enquote{Let the earth sprout a great many paradigms and programming patterns,
	 and binary trees bearing random number generators in which is their seed,
	 each according to its kind.}
	And it was so.
	And God saw that it was good.
	And there was evening and there was morning; the third sprint.
	\end{minipage}
	\end{center}

	\hfill\textit{--- the SCRUM--Witch, citing her scripture}
	\vfill
}

\newcommand\unintentional{
	\hbox{}
	\vspace{5mm}
	\begin{center}
	\tiny
	--- This page is unintentionally left blank ---
	\vfill
	:P
	\end{center}
}

% Fill with empty pages here so we don't have empty pages immediately before the cover
% Assuming there are n*4 pages of content left before the back cover,
% our target is {page num mod 4 = 0} – if it is anything else,
% fill the empty space with nonsense and a cheeky quote
\ifcase\numexpr \modulo{\value{page}}{4} \relax
% don't add any extra pages
\or

\unintentional
\newpage
\scrumwitch
\newpage
\thispagestyle{empty}
\unintentional
\or
\thispagestyle{empty}
\unintentional
\newpage
\scrumwitch
\or
\scrumwitch
\fi