As I was creating this document, I faced the question of which monster abilities should be considered magic and which should not... Since this division is somewhat arbitrary. For example: - Dendroid roots, - the ability of Imps and Specters to steal mana, - the anti-magic shield of Unicorns, - magic resistance of Crystal Dragons and Dwarves, - Vampire Lords with their ability to replenish their health points, - the ability of Behemoths to reduce the enemy's defense, - the resurrection of Phoenixes, - the regeneration of Trolls and Specters. Is this magic or not? For now, I am inclined to believe that this should not be considered magic - just innate abilities of the units. But the question remains open. As I continue, I see that the ability of Bone Dragon Specters to reduce the morale of enemy units corresponds to the basic level "Despair" magic. Also, Devils and Archdevils create a permanent "Misfortune" spell of the basic level. This needs to be added... But does it work for all units? Added 1 minute ago

So, what about Imps? I heard something similar, that the mana drain directly depends on the number of Imps, something like 1 to 1. Is that true?

The reference says: "When the spell is used by the enemy, it organizes a Mana Channel and adds 20% of the mana used by the enemy for the spell to its hero." The number of units does not matter.