1) Invisibility allows one (or more) of the hero's units to become invisible.
Invisible units can act like normal units, but the enemy cannot see them until they try to move through them, stand on their tile, or ranged attacks are blocked. This causes the invisible unit to become visible and attack.
Also, an invisible unit becomes visible if all visible units are destroyed.
When surrendering, the cost of the invisible unit is not taken into account.
An invisible unit has the ability: Reveal, which makes it visible.
2) Illusion
Creates an illusion that everyone will see. It participates in combat. An attempt to attack it results in it dissipating (if it is an illusion of a spectral creature, this is not necessarily the case; a miss is possible).
Hero Phantom.
Creates a phantom of the hero, which is perceived as a hero.
The maximum distance of the phantom, as well as the accuracy of the enemy's identification, depends on the strength of magic.
In other words, in general, the enemy will see 2 heroes.
Identity Mask. Temporarily changes the hero's appearance.
For example, you can pass off a strong hero as a weak one.