Potion of Growth

One stormy night, a knight was in a overwhelming battle against the odds, knowing that he is weak, he knows that he will not survive against the opponent even if he had the will to keep going; he fought hard and well, but he is soon to perish.

Ashamed by the death of their weaker units, scientists, called rodents that never battle, they made a spell which made their weak units grow each time goes on and they decided that it worked very well, every faction wanted to use its unique power.

So they did, using it on every battle, and taking advantage of their strengths and destroy their enemies. They even have a name for it... They called it Potion Of Growth.