Equality and Difference (RiR) is a mod for 3.0(1).

The idea is interesting (similar creatures were in the seventh game), and an alternative could be made as an archer (base: a regular priest with a prayer and possibly a cleansing spell; the upgrade would be a more powerful version of the same, but with a larger arsenal of light spells; and the alternative upgrade would be an Inquisitor – Holy Word, mace, and generally, an inquisitor).
However, it needs to be tested, and that will be difficult...