Aionion is Inflection of Aion

[HSong]

Matt 25
41 Then He will also say to those on the left hand, 'Depart from Me, you cursed, into the everlasting fire prepared for the devil and his angels:
Rev 20
10 The devil, who deceived them, was cast into the lake of fire and brimstone where the beast and the false prophet are. And they will be tormented day and night forever and ever.

Again, I will not stop promoting Christian Universalism. Same quotes

https://www.biblehub.com/matthew/25-41.htm

eternal
αἰώνιον (aiōnion)
Strong's 166: From aion;

aion means age. aionion is an inflection of the word aion. aionion means pertaining to an age. therefore, aionion does not mean an unlimited duration, because this age is that of a limited duration

Revelation 20:10 - Satan Cast into the Lake of Fire

And the devil who had deceived them was thrown into the lake of fire and sulfur, into which the beast and the false prophet had already been thrown. There they will be tormented day and night forever and ever.

www.biblehub.com

Again, we see the same aionion here
ever.
αἰώνων (aiōnōn)
Strong's 165: From the same as aei; properly, an age

so same explanation. age, limited, inflected as aionion, still limited.

God bless Jack