The “He’s God. He can do whatever he wants. “ is generally the false premise used by atheist in thinking that they are posing some kind of clever argument against God.
It is not true, therefore ANY argument for or against God using that premise is useless and a waste of breath.
If you're going to debate something, at least start with something that can even be remotely considered true.
The atheist, who starts out being a fool (which is also in the Psalms) does not understand the concept "God" enough to understand that his idea of "Whatever he wants" is jejune and won't hold water.
There are some theists -- usually those who find name calling and insult more congenial than thinking -- who are stampeded by the atheists who make bogus arguments out of their misunderstanding of God and willing, freedom and power, and the rest.
But it is illogical, ahem, to conclude that because SOME theists cannot argue against the abuse of the proposition, there is something wrong with the proposition. We should also consider that there just might be something wrong with the thinking of the theists in question. Other theists may be quite well prepared to affirm, interpret and explain the proposition in a way which is both responsible to Scripture and to reason and at least thought provoking to the atheist.
If you're going to debate something, at least start with something that can even be remotely considered true.
Let all see and let the record show that when you are not castigating Catholics for failing to yield to Scripture you are characterizing a clear statement of Scripture as something that cannot even be remotely considered as true.