I've already said this sequence is possibly my favourite in the whole of Shades and this page is possibly my favourite in the sequence.
I love the way the exposition in the centre panel just rolls neatly into the rather touching exchange between Boo and the Shaman; and Harsho's evocation of Victorian London is absolutely superb (of course!)
The idea behind it grew from the fact that super heroes are effectively ageless. Rather than just sweep that under the carpet as mainstream comics often do (giving rise to the need for a retcon every few years), I decided to embrace their ageless quality and explain it within the comic itself (i.e. through the concept of "spirits" fusing with those of the characters).
It was only a small step from there to realise that if Boo and the Shaman, for example, have been around for thousands of years, it's unlikely that they would have only taken to a career in do-gooding during the last couple of decades. When we eventually get to the end of Shades, I'd love to do a number of short stories with these two at different periods in history. Boo vs Napoleon? No contest!