Deuteronomy 7:15
15 And the Lord will take away from thee all sickness, and will put none of the evil diseases of Egypt, which thou knowest, upon thee; but will lay them upon all them that hate thee.
Evil is the Just Deserts Punishment of Evildoers. When Evildoers are Punished with Evil that is a Good thing. For example, when Elohim/God smites Evildoers with Evil Diseases that's a Good thing.
Also Evil is to Try the Saints in the Struggle for Perfection.
Genesis 3:1
3 Now the serpent was more subtil than any beast of the field which the Lord God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden?
Revelation 12:9
9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
Yes, most certainly Elohim/God created the Devil/Satan. The Satan/Devil is Elohim/God in its Lowest Form. Elohim/God is Good and Evil Being All Things. Elohim/God has given it's creation the Choice between Good Side of Elohim/God and the Evil Side of Elohim/God.
Ephesians 4:6
6 One God and Father of all, who is above all, and through all, and in you all.
There is Nothing that Exists Outside of Elohim/God, otherwise Elohim/God would not be Elohim/God. Elohim/God is All-Encompassing and All-Containing. Everything that Exists is part of Elohim's/God's Body. A limited Consciousness does not understand this.