He hadn't seen ... he hadn't seen his angel look like that in years. In centuries. Not even at the Almost-Apocalypse. That had been Aziraphale ready to die. This ... this was Aziraphale in full, no-holds-barred avenging angel mode. This was the Guardian of the Eastern Gate. This was the agent of Heaven who'd spent four thousand years casting him down upon the earth, who'd fought him above Babylon, above Giza, above Jerusalem. This was the angel who'd torn him from the skies time after time, back before the Arrangement, back when they'd been alone amongst enemies, without back-up, without help, and bound and determined to knock seven bells out of each other until Judgement Day or death, whichever happened first. This was the Wrath of God come to defend his people.
Crowley frightens six demons to death.
His mind poured out, clawed into them, crawled over them. Ripped them open, shredding consciousness and plunging into the lurid depths of the subconscious. Pressing, with extreme fucking prejudice, the big red button marked 'TERROR'.
Aziraphale nuking Hell with faith.
And Crowley thought, wow, someone's gone and made Aziraphale angry.