Hmm.. several questions here actually..
I have two clerics in my group, one turns undead, the other rebukes them. Next adventure will feature undead, so I thought I'd better check this out first.
1) What happens when one cleric tries to turn (destroy) the undead, while the other tries to rebuke (command) them? Is it simply a matter of initiative? E.g. the evil cleric wins, and commands them. Then the good cleric destroys them. Do they still make the check against the undeads HD, or do they make the check against the other cleric controlling them?
2) The player playing the evil cleric, doesn't want the other to find out which god he is worshipping. Alas, the secret of him being evil isn't that secret anymore, not with him using Death Touch on numerous occasions. Will a Turn Undead action on his part force him to brandish his holy symbol in such a way that the others cannot avoid to see that he follows Asmodeus? Or can he hide this in any fashion?
3) How about when he simply casts spells with DF component? Must he brandish this as well?
1. Beats me.
2. I think that if you're rebuking and casting spells with DF, you're going to need to be showing your holy symbol and/or saying Asmodean kinds of things that would give you away. I don't know that the rules address this explicitly, but that's the common sense thing I'd rule as a DM.
I think it'd be fair to have a feat that lets you conceal your exact faith (just have the DF on you). Or a domain power; it seems like this would be a common use case for secretive evil deities so you could sub it unto e.g. the Trickery domain...
From my understanding of the rules when ever a cleric uses turn/rebuke he HAS to brandish his symbol in such a way as to provide the focus for his gods power. It states something to that effect under the turn/rebuke section in the PHB.
As far as turn vs rebuke it first comes down to initiative as far as the turn. If the good cleric makes'em go poof then the evil cleric cant do much about it. On the other hand if the good cleric just turns them then the evil one will have to overcome first the HD Then the turn attempt of the good cleric. The rules for breaking a turn are in the PHB 3.5 under turning. If the evil cleric wins init. then his control over the undead has to be overcome by the good cleric as a bolster attempt.
Hope this helps good gameing and I dont envy you running a game with a good and evil clerics, thats a war waiting to happen.