To work with the DeployReserveHero() function, you need to add a hero to a player's reserve and ensure that this hero is not on the map.

Through experimentation, I found that I can summon a hero from the reserve for StartCombat(), but he is neutral, even if I assign him an allegiance in the editor. However, I want to initiate a battle with a specific character who is already on the map, but the function refuses to recognize him.

I've seen this script implementation in other games. Perhaps you could suggest how to extract a map from a campaign? Then I could delve into the code myself and share the solution if you're interested.