Heroes of Annihilated Empires Hints & Cheats

While playing the game, press ENTER, type one of the following codes and press ENTER again to apply the code. Change the numbers for the desired result.

Don't give a lot of XP at once or your final warrior may become weaker. Its because you'll loose the option to reload at every levelup if you don't like the bonuses.

While playing, press [ENTER] to bring up the chat window. Type
any of the following cheat codes. CODES ARE CASE SENSITIVE!

When you get a potion that gives you permanent bonus (e.g. potion of endurance for +1 resistance), pause your game and click on the potion as many times as you want. The additional bonus will last till you complete the current level.

I've checked this for health, resistance, attack rate and damage bonus potions. Works for the EU release of the game. Dont know about US, JP or AU releases.