With Beginning Dominance you can begin "the story of how I became omnipotent and got every chick I want".

With Midpoint Dominance you can make it so in the middle of your adventure or life, something happened. You can choose what happened. It can be anything you want as long as it occurred somewhat in the middle of something. Not just life or adventure. You can also make something happen in the middle of playing a game, in the middle of cooking etc.

With Conclusion Dominance, you put an end you your weaknesses and morality to become powerful. Another example is you can create for example Captain America's shield by ending it's nonexistence, making it existent.

Beginning Dominance: You can make your own take on genesis, your adam and eve.

Midpoint Dominance: You can make history itself, beginning and ending doesn't matter, it's the journey, you have the details. You make the story.

Conclusion Dominance: Create a beautiful way to end everything, personally I like black hole absorbing a second big bang, consuming everything instantly. But you want style, which is way more ironic, do that rapture thing, the afterlife has it's revenge on us, killing the living from the dead.