5th Business spread
BLFO, your question really intrigued me. I would not normally go to Tarot for such a question, because I'd think the writer would have built all these influences into the character already, which is a construct, not a real person, but the more I thought about it, the more interesting it got. Thinking back to my favourite author, Robertson Davies, and his novel about the stage, actors, opera etc Fifth Business, here's the suggestion I came up with.
*************4******
*******S 1(sideways to cross S)****
******2*************3****
*************5**************
Go through the deck to find a significator for the role. This will get you thinking about the character. place the card face up.
1st, put a card crossing this, this is the main struggle the character faces, it is the visible struggle within the plot-line
2nd, a card below and to the left, the hidden past, the subconscious influences.
3rd, below and to the right, the views of other characters.
4th, above, to the centre, the aspiration and desire of the character
5th, below the spread, 5th business, the extra un expected influence that sets the pieces in motion.
Good luck!