"The Restitution of ALL things" = horsefeathers! and unScriptural.
The Final eternal spiritual state and realm for BELIEVERS ONLY...
This includes everyone in the universe, including the dead and demons:
Rev.5:13 And every creature which is in heaven, and on the earth, and under the earth, and such as are on the sea, and all that are in them, heard I saying, Blessing, and honour, and glory, and power, be unto him that sitteth upon the throne, and unto the Lamb for ever and ever.
John speaks of "every creature" & to emphasize this again he repeats "and all that are in them":
Rev.5:13 And every creature which is in heaven, and on the earth, and under the earth, and such as are on the sea, and all that are in them, heard I saying, Blessing, and honour, and glory, and power, be unto him that sitteth upon the throne, and unto the Lamb for ever and ever.
This worship (v.13) uses the same worshipful words as the redeemed of vs 9-10 use in v.12:
12 Saying with a loud voice, Worthy is the Lamb that was slain to receive power, and riches, and wisdom, and strength, and honour, and glory, and blessing.
All this being in the context of salvation - "the Lamb that was slain" (v.12 & 13).
Revelation 5:13 speaks of a time beyond the punishment in the lake of fire.
Rev.15:4 Who shall not fear thee, O Lord, and glorify thy name? for thou only art holy: for all nations shall come and worship before thee; for thy judgments are made manifest.
This sounds like just payback, not endless annihilation or tortures:
Rev.18:6 Reward her even as she rewarded you, and double unto her double according to her works: in the cup which she hath filled fill to her double.
Rev.21:5 He who was seated on the throne said, “I am making all new!”
"In the Book of Revelation, the phrase "kings of the earth" appears 7 times in Rev 6:15; 17:2,18; 18:3,9; 19:19; 21:24. In all but the last citation the kings of the earth are portrayed in Revelation as aligned with Mystery Babylon and are the enemies of God. Yet, in 21:24 we find that the "kings of the earth" will one day bring their splendor into the New Jerusalem. One must therefore ask how or why are the kings of the earth who are consistently and without exception portrayed in Revelation as evil and unrepentant, allowed into the New Jerusalem where "nothing unclean will ever enter it, nor anyone who does what is detestable or false, but only those who are written in the Lamb's book of life" (21:27). I cannot find any scriptural evidence that these kings of the earth are any different than the previous references. Therefore the only conclusion I can arrive at is it that appears that even the kings of the earth after having spent some unknown time in the lake of fire will one day repent and be allowed to enter into the New Jerusalem."
That recalls some other passages about kings:
Psalm 72:11
Yea, all kings shall fall down before him: all nations shall serve him.
Psalm 102:15
So the nations will fear the name of the LORD And all the kings of the earth Your glory.
Psalm 138:4
All the kings of the earth will give thanks to You, O LORD, When they have heard the words of Your mouth.
Isaiah 60
2"For behold, darkness will cover the earth And deep darkness the peoples; But the LORD will rise upon you And His glory will appear upon you. 3"Nations will come to your light, And kings to the brightness of your rising.
Isaiah 62:2
The nations will see your righteousness, And all kings your glory; And you will be called by a new name Which the mouth of the LORD will designate.
Revelation 21:24
By its light the nations will walk, and into it the kings of the earth will bring their glory.
https://www.tentmaker.org/books/hope_beyond_hell.pdf