The Drain scale is nulled by the fact that you have death and can make Skull Mentors. But that is only one option to give MR.

More often than not, the longer that Ermor survives with a good dominion the stronger it gets.

Ashen Empire is particularly nasty with 9 Death and 8 Bless Effects as Unholy Knights of the Seplechure are plentiful and can form a strong core of your armies against banishment.