>Hello,
>
>I wonder if tigerclaw will render a shaman (or any communer)
>unable to use its maledictions on me.

Nope. You don't need to speak to commune.

>Since, as an assassin, I can't hide from duergar Shamans, any
>tips on how to win a fight (beside using their light and wrath
>vulns and dual wield) would be most welcomed: I've been
>fighting many and only able to flee or die.

1) If you're hidden in forests or many other kinds of wild terrain, a duergar can't see you.

2) NPC healers and malediction cure potions/pills are helpful; so is bindwounds.

3) Having a teleport potion in your inventory is a good way to escape if you have to.

4) Getting the shaman's weapon and/or shield out of his hands via your crippling techniques (mostly kote/kans) is usually possible. While this doesn't stop communing, it will reduce their melee damage and more importantly, their ability to deflect your melee attacks.

5) Command denial (lag) attacks will slow down communing. Throw is a good early option and remains good in the case that protective shield isn't up; otherwise, you're probably looking at mountain storm kick or double spin kick.

6) -spell gear will make most communes less likely to land; +strength gear will make it harder for poison/plague/weaken/famish/wither/etc. to disarm you.