1) There is a counterspell against the holy word, and besides, it will still be weaker than the unholy word of the Necropolis;
2) You can also apply a general punishing strike, which means 1 turn of your hero is wasted;
3) As I already said, exorcism does not remove ALL negative spells at once (although I am not entirely sure about this):
4) The rune of incorporeality is useless; it only allows for one missed attack at most. And besides, don't forget that Naadir has a LOT of ghosts that solve this problem:
5) Berserker rage is not bad, but you need to find it;
6) Resurrection is good to use, but only low-level creatures are well-restored;
7) In short, let's play through Hamachi and see... 2 turns of your hero won't be enough to even finish off the skeletons. Don't forget that the terrain can be against you.