10% - the hero pays 40,000 gold once, and the growth of level 1 creatures increases by 100% (if no buildings have been constructed to increase growth, then with the construction of buildings to increase growth, 100% - this is the data from the last creature growth, that is, if the creature growth was initially 26 and then became 78, then 100% is 78).
20% - the same, but for level 2 creatures, and the growth is 90%, the price is 50,000.
30% - level 3, 80%, 60,000.
40% - level 4, 70%, 70,000.
50% - level 5, added after the construction of a special building, the Tower of Ashi (built using the Tear of Ashi), 60%, 80,000.

Special building - Thieves' Guild - the ability to steal resources from the enemy for a large sum of money.

Abilities - steal resources (excluding gold) 10 units (rare resource) or 20 units (wood or ore) for 7,000 or 14,000 gold.

You are also making things up about the faction.