The most powerful hero of the Dungeon faction.

Kifrah is valuable for her leadership in the early game. As mentioned, Empathy is a very valuable skill for the Dungeon faction. She is more effective than a third-tier Sorcery hero.
However, in certain situations, it's better to choose different heroes.

The weakest aspect of the Warlock is the fragility of his army. The Warlock's army needs to last as long as possible while the hero casts powerful spells – and this is Kifrah's significant advantage in the late game. Armored Minotaurs with 40 HP will hold the line while Kifrah casts spells. Any other hero will run out of steam faster; Furies and Griffins will be defeated much faster than Minotaurs, by a factor of 2-3. Yes, with their initiative, Minotaurs won't deal much damage, but the hero will deal a lot of damage while the Minotaurs hold the line.