3 and 4: Light and Dark
In the beginning of every stereotypical creation myth, there is nothing but darkness.
Then, there is suddenly light, and in the Nintendo dimension's creation, that light came in the form of a giant gloved hand.
On the first day, Master Hand wandered the darkness and discovered portals that peered into the various worlds in the realm. The worlds had been created around the same time that he was; this led Master Hand to assume that he accompanied creation to watch over it.
On the second day, Master Hand discovered beings wandering in the darkness. They called themselves the Subspace Army, wandering the world they dubbed Subspace to look for the person that could lead them. Master Hand had thus learned that darkness is not inherently evil - much of the Subspace Army was otherwise nice and friendly. Darkness is nothingness, and from nothingness comes infinite possibilities.
On the third day, Master Hand discovered that he could mold the energies of Subspace into objects with his mere thoughts. He learned that any being aside from those born in Subspace could do that - however, Master Hand, as the hand of creation, is the being that could take advantage of Subspace's creative energies the most. Through his power, he created a grand palace and homes for the people of Subspace, and so the people rejoiced.
On the fourth day, Master Hand realized that Subspace does have a concept of time and it indeed was the fourth day.
On the fifth day, another being of light came into existence. Along with the concept of darkness not being inherently evil, light was not inherently stable; that concept was learned in the form of Crazy Hand, the hand of destruction, who proceeded to utterly fuck up the world.
On the sixth day, Master Hand and Crazy Hand battled. Fears ran that if Crazy Hand won the fight, he may use the creative properties of Subspace for destructive purposes - not just toward Subspace, but toward the worlds that connected to it. In the midst of the chaos, the constant misuse of Subspace's powers created a flawed creation: the Shadow Bugs.
On the seventh day, the fighting ended, Master Hand victorious. However, when Master Hand confronted Crazy Hand, he discovered that indeed, the other hand had no proper grip on reality, and though chaotic, not truly evil. Instead of banishing Crazy Hand as he originally planned, he decided to make Crazy Hand co-leader, and soon came to see him as a brother.