Hey all,
Czernobog is intended to be a Defender.
There was a discussion prior to if Czernobog were more a Defender or a Generator, but felt that Czernobog was more like Gorgotha (Defender) and less like Ragnagord (who is a Generator)
As Czernobog has the skull damage reduction as well as mana generation from creating Gems.
Just in case, there is a breakdown and Gorgotha as an example in the Troop Roles article;