UNIT - Creature Balance + Visual Changes

Shamans also have an alternative, and it doesn't have a drawback, which in itself is a fair counter. As for dark magic... isn't the slow effect given to them by the developers considered dark magic?

You're comparing tier 1 and tier 4. It's the same as comparing stone spikes to a meteor shower. The alternative is very weak. What's the point of this attack without a drawback when I spend the whole battle casting slow on the enemy stacks and acceleration on my own? Play against a worthy player who uses Orcs, and you'll understand what they're capable of, and this dark magic gives them even more opportunities. And what prevents me from splitting the shaman stacks in the final and blinding all the enemy ranged units, and in melee combat, few will have a chance, thanks to the blood magic, which makes the creatures very durable and also gives huge bonuses.