Just curious if they implemented that particular rule.

Also, do any enemies use turn undead against you?

I always have a Paladin in my party (no GB games that cater for evil parties anyway), and I've never seen it happen.
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No, and there are only two sides to a battle and n̶o̶ ̶p̶l̶a̶y̶e̶r̶-̶c̶o̶n̶t̶r̶o̶l̶l̶e̶d̶ ̶u̶n̶d̶e̶a̶d̶ disregard that, PoR has some, so n̶o̶ ̶a̶g̶a̶i̶n̶ probably still not.

O.o and I always thought it was an engine restriction, along with other unimplemented neat / iconic / obvious stuff (equipment queries for one). There should have been way more awesome original O.o-inducing things done with an engine which allows for PC undeath.