The essential reality is men are limited in their understanding, by their very nature.
Men's definitions and thought process cannot erect barriers to God's will.
Maybe God does that, in some way far beyond man's understanding.
Maybe God plays games with himself, to stave off boredom, to make an almost meaningless argument about the nature of reality.
Men are limited, but within our limits, we can do much.
Yeah, I get that man has a very limited understanding of those concepts. Unfortunately, “omnipotence” and “omniscience” are still defined in those manners. Defined by God Himself even.
And besides, most times, stories depict those who’s motives no one could comprehend as being bad guys. Like Abeloth from Tales of the Jedi, or the Patriots from Metal Gear Solid 2.
And who said anything about erecting barriers? Last I checked, God cannot be restrained anyhow.