The answer is complicated because the concept of satan evolved over time.
Here, I give a simplified yes answer.
Ezekiel 28:
This is confirmed in (NIV) Isaiah 14:
Was Satan a cherub?
I think so. I think the evidence is pretty good.
Here, I give a simplified yes answer.
Ezekiel 28:
The prince of Tyre was a type of Satan. Like Satan, he was proud.1 The word of the LORD came to me: 2“Son of man, say to the prince of Tyre, Thus says the Lord GOD:
Like Satan, he was wise:“Because your heart is proud, and you have said, ‘I am a god, I sit in the seat of the gods, in the heart of the seas,’ yet you are but a man, and no god, though you make your heart like the heart of a god.
Pride in everything is a recurring theme for Satan.5 by your great wisdom in your trade you have increased your wealth, and your heart has become proud in your wealth.
Beauty is another attribute that the prince of Tyre and Satan were proud of.11 Moreover, the word of the LORD came to me: 12“Son of man, raise a lamentation over the king of Tyre, and say to him, Thus says the Lord GOD:
“You were the signet of perfection, full of wisdom and perfect in beauty.
That's the connection of the satanic creature in Eden with the creature that is called Satan or the devil in the NT.13 You were in Eden, the garden of God;
He was anointed.every precious stone was your covering, sardius, topaz, and diamond, beryl, onyx, and jasper, sapphire, emerald, and carbuncle; and crafted in gold were your settings and your engravings. On the day that you were created they were prepared. 14 You were an anointed guardian cherub.
This cherub was blameless initially but he changed:I placed you; you were on the holy mountain of God; in the midst of the stones of fire you walked. 15 You were blameless in your ways from the day you were created, till unrighteousness was found in you.
Again and again, the prince of Tyre and the satanic creature were proud of their beauty and wisdom.17Your heart was proud because of your beauty; you corrupted your wisdom for the sake of your splendor.
For the prince of Tyre, God would expose him before kings. For the satanic creature he would be cast out of heaven.I cast you to the ground; I exposed you before kings, to feast their eyes on you.
This is confirmed in (NIV) Isaiah 14:
That's crazy arrogance, conceit, and self-deception. It's delusional madness!12 How you have fallen from heaven, morning star, son of the dawn! You have been cast down to the earth, you who once laid low the nations! 13You said in your heart, “I will ascend to the heavens; I will raise my throne above the stars of God; I will sit enthroned on the mount of assembly, on the utmost heights of Mount Zaphon. 14I will ascend above the tops of the clouds; I will make myself like the Most High.”
Was Satan a cherub?
I think so. I think the evidence is pretty good.