Cheat Codes for Tribes of the East.

@TakeAwayHeroExp("hero's script name", amount of experience)
It's unlikely that you'll be able to make a hero unlearn spells.

I haven't experimented with spells (there might be an unlearn_spell command), but you can unlearn (remove) skills:
unlearn_skill
the skill and ability numbers are the same as for the add_skill command

But I'm more interested in something else:
1. How do you place a Mentor at a selected location on the map? (manually editing the hero is tedious, especially if the opponent "trained" him)
2. How do you change the level of creatures that can be recruited at a Fortress? For example, instead of recruiting 4th-level creatures, how can you recruit 4th and 5th-level creatures at the Fortress?
3. How do you change the race of a Fortress? Or how do you place a Fortress of the desired race on the map at a selected location? (sometimes a random map is interesting, but the conditions are too uneven, so you have to help the opponent or yourself)
4. How do you hide the map again after making such changes? (again, so as not to see the opponent's actions, so that the game is more interesting)

P.S. Everything that is indicated in points 1-4 for a map created in the game using the GSC (Game Scripting Compiler) could be done using the H5_MapEditor.exe editor.
But... The editor corrupts the map beyond repair: before loading, the map file had a certain size (about 600...800Kb), and after loading and saving the changes, it's about 0Kb.
I remember that the map editor in Heroes 3 worked without problems. But in Heroes 5, there's some kind of problem with it...