"Necropolis" - changes to creatures of levels 6-7.

What's the point of weakening them so much? The result will be the same – dead units, but not with a death blow, but with lingering presence. 20 defense and 120 hit points – just like a level 6 unit. They will still die in one hit, with a 50% chance.
Ghosts are incorporeal, and their stats are no better than others.

I was talking about reducing defense at 150 hit points, not 120. Damage dealers should be fragile; otherwise, it creates an imbalance. Ghosts are not damage dealers, and besides incorporeality, they don't have any particularly significant abilities, which are just added to Messengers as a bonus. And where do they have "stats no better than others"?