Different but the Same
They were opposites as Theta and Koschei and still are as The Doctor and The Master. The Master is the dark to The Doctors light, same as Koschei is the dark to Theta's light. They even look opposite to each other; Koschei has straight black hair and ice blue eyes while Theta has curly golden hair and light brown eyes. They still look opposite to each other, The Master with his shaggy blond hair and crazed blue eyes and The Doctor with his mad spiky brown hair and old brown eyes. Even their ideas are opposite, one wants to heal the other wants to hurt, one wants to help the other wants to control. Theta and Koschei were the best of friends, The Doctor and The Master are the best of enemies. They are the moon to the others sun. The day to the night. The water to the sky. So different but they fit together so perfectly. They are mad, dangerous and fantastic. They could both easily change, but that doesn't mean they ever will. They could easily become best friends again, but that doesn't mean they will. They are like winter to summer and spring to autumn. They are as opposite as off to on and up to down. They are like two sides of the same coin, so different but exactly the same.