Changing the hero's starting skills.

In the editor (before starting the game, of course). If the hero is already placed on the map, open their properties, and if not, but you want to hire them in the tavern — open the "Heroes" tab and click Properties, and there you can change it as you need.
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Hello, thank you for the reply, and I apologize for responding after so long. I want to change the Necropolis hero Vokial (specialty: vampires) base skill Artillery (Ballista) to something else, Defense for example. And I want this skill to be present on generated maps. Could you write what exactly the editor is called in which such edits can be made? Will it work if I play with a friend in an online lobby?
Thank you in advance.