I run a Scarred Lands game, but I am not so familiar with this one. Is it the spell that lets you catch someone flat-footed by attacking his shadow? If so, there is a similar spell in, um, PHBII I think, and all it does is let you make one melee attack/round (maybe just one attack) at range, explaining it as the caster reaching through the target's shadow to hit them.
A gentle reminder about the specs of this spell might help!
As an aside, I threw Prevarication's Bounty right out the window, and either modified or substituted dozens of other RR or RRII spells, so if you have more questions, I'd be happy to give my opinion on them, if it would be of any help.