There is a simple, logical theorem to explain.
First, we establish some facts.
I play Ike.
No one we know plays Snake. We didn't even know what Snake's moves are.
We beat Elliot, most of the time at least, who plays Ike.
We do not beat Snake.
Hence, it is only logical that we were able to defeat the more skilled player because we were familiar with the moves and strategies of that character. We lost to the less skilled player because his moves and strategies are completely alien to us; even if your strategies are very different from those of other Snakes, we were still unfamiliar with the basic moves. For example, we didn't know that Snake's upsmash, the mortar, came back down after it was shot upward.
In conclusion, things should be settled when we rematch. I don't want to make any claims, but my friend plays Snake as an alt, so I should hope to do better.
What flaws do you find in my argument? Please respond courteously, I don't want the Ike forums to gain a bad reputation. =P
Edit: For anyone interested, on the subject of custom moves, my friends have seen a few moves I've done and named them. A few examples of such amazing moves are the Grand Zareidriel, the Hillbilly Nutcracker, the Napalm Death, and the Triple Mega Ultra Zareidriel. They can be found in the No-Nonsense Ike Manual. 8D