You still didn't answer the question.
Who created Satan?
Technically, God created Lucifer -and Lucifer then made himself Satan (Adversary) by choice.
That is not to say that God did not know it was possible.
He knew it was possible -just as he knew it was possible for Adam and Eve to sin.
God created the situation which allowed for individuals to will and do evil -but he did not create any evil beings.
Eze 28:14 Thou art the anointed cherub that covereth; and I have set thee so: thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire.
Eze 28:15
Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.
The choice to do evil was theirs -but they did not necessarily fully know or believe it was evil.
God created new creative beings -which means they had the ability to make choices.
Those new beings did not have experience -therefore they were not able to know for certain that God was who and what he said he was -or that what he told them was truth.
Even Lucifer's sin was initially somewhat in ignorance.
To know God is God and tells the truth requires experience.
That is what is meant by the following......
Isa 45:6
That they may know from the rising of the sun, and from the west,
that there is none beside me. I am the LORD, and there is none else.
Isa 45:7 I form the light, and create darkness: I make peace, and create evil
: I the LORD do all these things.