Favorite hero from Dungeon.

The hero isn't the best, but if you develop him with an emphasis on the Warrior skill, he's quite good. The Sinister's ability is more interesting, of course, but it doesn't add anything to the troops, and you shouldn't rely on just one magic spell. Moreover, his ability only works in prolonged battles, like sieges. In a normal battle, you can cast the enhanced Earth Shock spell three or four times, and even a regular hero can handle it.

I've already expressed my opinion about the Dungeon heroes, so I'll just add my two cents in support of Vayshan.

A Dungeon hero developed purely in magic has a very hard time against a well-developed Academic or Gnome.

Therefore, you have to go down the path of strength. And in this case, Kifrah and Sorgall look the most optimal.

As for Kifrah specifically, she slows down a bit at the start, but she looks extremely strong in weeks 6-7.
With the speed aura, tactics, and +1 speed boots, it's no problem for the Dungeon to get minotaurs and hydras to the enemy in one turn (if he hasn't developed tactics), and that's devastating.
And instead of Inspiration, the General speed increase from the "Attack" branch looks just as good, especially in combination with Keen Mind.
And Retribution becomes a critical perk, as it significantly enhances the effect of the first strike.
Artifacts for attack/defense (which will definitely be available) and initiative (which the Dungeon will have by week 6) become a priority.

P.S. It's interesting how things are working out between us and Vayshan. On the discussed issues, we either have almost identical opinions, or practically opposite ones. There's no middle ground.