Fiat vox veritatis, ruat caelum.
Satan has been condemned to allegorical beheading by guillotine, for the irony.
Immortals do not die from a mere decapitation. He will not be cast out into the utter darkness. Satan's body and soul will be incinerated in fires of Khaos wielded by pure hatred, until neither smoke nor ashes remain. He is to be Destroyed so utterly it will be as if he was never Created in the first place.
Feast upon his sorrow, agony, and terror, as he feasted upon yours.
Satan will leave behind an egregore and several billion worshippers.
Satan's egregore will be drowned in a vat of the waters of Lethe. The water will be boiled in the heat of the holiest pyre. The vat and its residue will, like its progenitor, be incinerated by the fires of Khaos.
Fiat vox veritatus, et pereat mudus.
Satan has been judged guilty of many crimes recognized by mortals and immortals alike. His greatest crime was being weak.
Satan was not the devil. Satan was the worshipper of devilry in and of itself. He allied himself wholeheartedly with disharmony and dissonance. Such faith is as lethal as an execution. His trial, ultimately, was deciding only between a slow death and a quick one. His own beliefs would have stripped him of his immortality, and he would have slowly aged, as a mortal, to nothing. However, he will not be permitted to drag any other beings with him. If they wish to walk the cliff and to jump off, it will now be only on their own initiative.
God's glorious party shall be made lesser, by one guest.