One thing is for certain. This supreme creator can never be the arsehole...
If such thing existed it could be anything and have any purpose. The idea that a "God" would exist to serve some humans is yet another baseless assumption based on wishful thinking. In fact if a creator existed it is more likely to be an "asshole" (from our perspective) since "he" would have created the universe to serve some of "his" needs and we are merely being used, like bacteria in a petri dish.
Lets take the example that T_C gave earlier:
If humanity were to create some form of artificial life in a computer...
Who is the "God" of that "artificial life in a computer"? More likely the creators of this "software" are more than one. And those that are using the "software" don't even have to be the same as the creators. In fact many different copies of that "artificial life" universe could simultaneously be run on many different computers by different users.
And what would be the purpose of this software? If you create something it is more likely that you create it to serve your needs or the needs of those who use your creation. You don't create an object in order to serve the needs of the created object. So if we were purposely created, then our more likely purpose would be to fulfill some needs of the creators and we are nothing but disposable objects who are being used.
And even if humans were to run some "artificial life in a computer" this wouldn't mean that Humans are immortal and all powerful. A human would have the power to "turn off" a universe running in his computer or affect it in various ways, but he still wouldn't have the power to make himself immortal.
As I wrote in an earlier post, the theists make a lot of baseless assumptions. The "Intelligent Design" is just one baseless assumption. Then they make a lot of other baseless assumptions, like that the creator has to be a single entity, that the creator is also an active "operator" ( a creation can exist apart from its creator), that the creator still exist (a creation can outlive its creators), that this creator cares about each and every one of them on an individual level and that this creator has as a purpose to reward them and serve their needs.
So it is a chain of baseless assumptions because the "Intelligent Design" theory on its own is not enough to serve the psychological needs of the theists.