New here? I'm Roha — want a quick tour?
Arengar, I also leveled up Zehir with Light, Summoning, and Empathy skills instead of Combat skills in the campaign, and I invested heavily in the Leadership skill with a mentor. Zehir was flying through the levels like a phoenix. No enemy could cast a single spell because Zehir managed to cast a counterspell and cast spells for himself. Fortunately, there were no Necromancers with Combat skills among the enemies. But even if it's not possible to get Leadership on the map without a mentor, a mage with Light and Summoning is always combat-ready, even without Empathy and without Combat skills. The main thing is, there's no risk.
In my opinion, the best ability belongs to the Elves, and I would put the Warlock in second place. The Gnomes' super ability is somewhat similar to the Elves' ability, but with the opposite effect, while the Knight's ability doesn't appeal to me at all.

Arengar, even if you had 100 luck, the probability of a successful attack in battle would be 50%. The fact that it's more than 5 has significance only in version 3.0 when the enemy has the ability to reduce your luck. I don't level up Special Ability (SA) for either elves or dwarves.
although the Haven SA is seriously underestimated here simply because it doesn't look as impressive as the others.
The Sylvan faction, and the heroes of this Castle, have absolute luck. I remember the first time I saw this skill (in the original 5th installment), I was amazed. Constantly attacking with luck – that's what I'm talking about. Just imagine Master Archers under this skill, shooting point-blank at anyone.
It's just that Urgash's Call is very difficult to upgrade... I tried using ArtMoney to do it, but it didn't work. Instead of fire arrows, it always gives speed magic. But, for example, Tactical Expertise is quite easy to upgrade, and I think this imbalance is not good.