The only thing that distinguishes this hero from a Knight is the presence of the Artifact Master skill. Everything else is the same as for a Knight. The special ability is quite specific, so it's better to develop it.
Hmm, so what am I playing then? :)
https://c2n.me/3RZDbhc, the hero's special ability is Avatar of Death.
Finally saw the Hellspawn - 4 of these creatures near the mine quickly defeated the entire army shown in the screenshot. :)
I took 2 necessary skills, but I still lose in the desert, what's the problem? (Turns out, the problem was taking the quest in the desert).