Rev 13:18 Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six.
Pay attention to the word 'count'. Here is the Greek definition:
G5585
ψηφίζω
psēphizō
psay-fid'-zo
From G5586; to use pebbles in enumeration, that is, (genitive case) to compute: - count.
And here is the root of that word:
G5586
ψῆφος
psēphos
psay'-fos
From the same as G5584; a pebble (as worn smooth by handling), that is, (by implication of use as a counter or ballot) a verdict (of acquittal) or ticket (of admission); a vote: - stone, voice.
It means to enumerate by stones worn smooth over a long period of time. To simplify that, it means to discover or learn something by long time study.
If you study over a long period of time, you will discover that Revelation 13:8 means that satan, that man of sin, the son of perdition returns to this earth at the 6th Trump, the 6th Seal, and the 6th Vial.
2Th_2:3 Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
There is only one 'named' son of GOD that is sentenced to death at this time and that is satan, the son of perdition. Perdition means to die.
Here is where he was sentenced to death:
Eze 28:18 Thou hast defiled thy sanctuaries by the multitude of thine iniquities, by the iniquity of thy traffick; therefore will I bring forth a fire from the midst of thee, it shall devour thee, and I will bring thee to ashes upon the earth in the sight of all them that behold thee.
The devil will be turned to ashes from the inside out.