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Fortress

Eymund

Starting units
Completed Rune
Earthquake
Ballista, Cart
Engineer
The hero disables mines, spending the rest of his turn. The cost to repair is 5000 gold for everyone except the hero himself – 2500. Broken mines are gradually populated by Bone Throwers. For every 5 levels, one more Bone Thrower arrives per day.

In my opinion, this isn't quite "Engineer," but rather "Mine Destroyer"!

It would be more logical like this:

Eymund
Starting units
Completed Rune
Earthquake
Ballista, Cart
Mine Destroyer
The hero disables mines, spending the rest of his turn. The cost to repair is 5000 gold for everyone except the hero himself – 2500. Broken mines are gradually populated by Bone Throwers. For every 5 levels, one more Bone Thrower arrives per day.

Mountain Engineer
The hero can improve mines that extract gems, crystals, gold, and ore.

And a female dwarf named Vasgeda [name borrowed from one game about dwarves] would be perfect for the "Mountain Engineer" specialization;)



Biography: Vasgeda became an orphan early because her father and many of her relatives died in one of the mines due to the natural greed of dwarves to mine as many useful resources as possible, regardless of the inevitable depletion of the mines. She delved into studying the secrets of mining and managed to find a way to improve some mines.

You might ask why some - it's simple, you need to introduce double randomness, i.e., any mine of the above type can either be improved or cannot be improved at all. If it can still be improved, then preferably by a certain constant percentage – a one-time operation!