The term "omnipotent" was used in reference to the emperor of Rome hundreds of years before it was used in reference to God. The term refers to the single entity to whom all powers of government belong and from whom all powers of government flowed. All of the government officials have powers delegated to them from the one who is omnipotent.
For instance, even today ambassadors are called "plenipotentary," meaning that the diplomat has power delegated from the leader of his nation to make decisions for his nation within the country he's posted. His powers are limited, however, to what was delegated by the omnipotent emperor...the nation to which he was posted. The ambassador to Spain has no power in Greece.
The military generals have limited delegated powers, the governors have delegated powers, the dogcatchers have delegated powers. But those powers only exist--in fact, the officials only exist as officials--because of the continuing omnipotent power of the emperor. They have power only because he has power, and they have that power only as long as it is the will of the emperor for them to have that power.
Omnipotence means that the emperor always retains those powers; the emperor's powers are not "given away" by delegation. At any moment, the emperor can personally exercise the powers he has delegated. The emperor can, at any time, go out and catch a dog or command the army, regardless of the fact that he's designated other persons to be dogcatcher and general.
He is the image of the invisible God, the firstborn of all creation: for by Him all things were created, both in the heavens and on earth, visible and invisible, whether thrones, or dominions, or rulers, or authorities—all things have been created through Him and for Him. He is before all things, and in Him all things hold together.
That last clause is important. God (as the Son) is the omnipotent entity of our created universe. No other power exists by its own will. All other power exists only because God continually wills it to exist.
Including Satan. Satan does not exist by his own will, he exists because God continually wills him to exist.