As I go through the legendary creatures for the remaining bi-colored combinations, there seems to be less and less creatures to pick from. As for Simic, which is green and blue, I was only given three options, two of which were just awful cards. So I took the one that was actually good for something and that card turns out to be Momir Vig, Simic Visionary.
Now Mormir Vig is a very weak creature, for he is a 2/2 for 5 mana. There is not a chance that you will be able to deal enough commander damage to win with him. The way you are going to win with him is by a lot of tutoring. Mormir's ability allows him to tutor creatures. If you play a green creature spell, then you get to look in your library for another creature and put that on top of your library. Now if you play a blue creature spell, you get to reveal the top card of your library and if it is a creature, you put it in your hand. I know that there are better ways to tutor, but what makes Mormir Vig worthwhile is if you play a blue and green creature. If you do that, both abilities activate and you can stack them, meaning you can choose what happens first. Obviously the way to do this is to look for a creature card, put it on top of your library, then reveal it and put it your hand. This is all a fancy way of saying "Look for a creature card and put it into your hand." Now that can be useful, because you can constantly tutor out some nice creatures by playing more creatures. The way to win with this deck is to just bring out the nastiest blue and green creatures and beat the pulp out of your opponents with them. Now that is fun!
You can buy Mormir Vig, Simic Visionary and all of the other cards that work well with him for a low price at http://www.mtgfanatic.com/!