Absolute skills

I apologize for interrupting your conversation, but I looked at the topic, and many people, to put it mildly, are not thrilled with the Knight's Special Ability (SA). Some even consider Unrelenting Force to be complete garbage. I'll try to prove that this isn't the case.

If we only look at the numbers, we get the following:
Let's say the hero's level is 27 (to make the calculations easier).
The Sentinel is cast on the thickest stack. Usually, this is Inquisitors, as they are much cheaper than Paladins (easy to train), have only 20 less HP, shoot, have no penalty in melee, and are also casters.
They are, of course, attacked. The hero deals damage to the attackers equal to a normal attack at level 30. That is, he takes out 1.5 creatures of level 7 per attack. With the SA, it's 3 times more. Is 4.5 Dragons per attack not enough? And he also casts Weakness from Dark Magic...
The only thing I would like is a rework of the Sentinel ability itself. So that for each hostile action directed at the "guarded" stack, the Knight would severely punish the offenders...

No, it's not completely useless. But I wouldn't specifically go for it – it ruins development (I would level up Light and Defense in a completely different way). Besides, you're a little mistaken – Dark Magic is not needed to level up the Knight's SA (in version 3.0), and it needs to be leveled up later, so that Sentinel deals damage with "Weakness," you need at least level 27. The problem is that there are always creatures to attack in the Knight's army, and by casting Sentinel on Inquisitors, you will only achieve one thing: they will be targeted last (which is, of course, important). I can imagine a few situations where the Knight's SA will work: Laslo or Iris (with armored units and griffons, respectively) will deal a lot of damage to the enemy, and if you also level up Dark Magic and cast Vampirism, it becomes almost overpowered, especially with combat griffons (I'll have to try it), but firstly, these are rare cases, and secondly, and most importantly, it requires at least level 26 (the overpowered build with combat griffons is level 32, considering "Luck"). In general, the Knight's SA is the worst compared to all the others.
P.S. It would be much more useful if the Knight had a hero like the Barbarian Krag.