. . . And I turned you to ashes upon the earth, in the sight of all who saw you. All who knew you among the peoples are astonished at you. You have become a horror, and shall be NO MORE forever. (Ezekiel 28:18 - 19)
This certainly is a strong indication that the devil can be put to a final death (destroyed) even though he is made of spirit.
Ezekiel 18:20 says that the soul that sins shall die. If this word soul would be translated as LIFE FORCE then it might be speaking to the angel realm as well as the human realm. Only God can prevent humans from being resurrected into a new body containing that human's life force and only God can remove the life force from the angelic hosts.
Satan convinced one-third of all the angelic beings to follow his rebellion (Revelation 12:3 - 4). Most of the rebellious spirits, now called demons or devils, have been incarcerated in a bottomless pit until such time that the Father will permit their release for their judgment.
6. And the angels who did not keep their own original domain (the KJV has 'first estate' while the NKJV has 'proper domain'), but deserted their habitation, He is holding in eternal bonds (some translations have 'chains') under darkness unto the judgment of the great day (judgment day). (Jude 6)
I can find no verse in the Bible that says evil, unrepentant spirit beings will be in torment or tortured forever.
The Bible tells us emphatically that when the elect have been raised into their spiritual bodies at the first resurrection, they will not only help judge the world but also spirit beings. This is what Paul told the church at Corinth.
Dare any of you, having a matter against another, go to law before the unrighteous, and not before the saints? Do you not know that the saints will JUDGE the world? And if the world will be judged by you, are you unworthy to judge the smallest matters? Do you not know that WE SHALL JUDGE ANGELS? . . . (1Corinthians 6:1 - 4)
Surprising though it may seem, the angels look forward to the day when the elected saints will teach them the deep things of God. Peter tells us that they want to understand these things but they do not even understand why they are doing what they are doing (1Peter 1:10 - 12).
Angelic beings were not promised to rule the world to come or to be sons of God.
"For He has NOT put the world to come, of which we speak, in subjection to angels. But one testified in a certain place, saying: 'What is MAN that You are mindful of him . . . ' " (Hebrews 2:5 - 6)
There will come a day when even angels will be judged to see if they have obeyed the laws of God, especially the Ten Commandments. Why do they need to be judged? Because at least one third of them have sinned and deserve death. Who will do this judging? Based on your Bible, it is those humans who have entered into the Kingdom as spirit born children of God.