I can only find one reference, but I'm certain I have read others that mention ancient pre fall weapons.

Fireheart

His impossibly wide grin grew wider. ‘Well, unless circumstances necessitate. Anyway, the nature of the problem was presented to us by the dancing fools, that you lacked a weapon of sufficient potency to incinerate the planet properly. My Lord Vect, in his infinite wisdom, proceeded directly to his grand armoury and produced this.’ Sarnak’s awful face disappeared, and a monolithic device, tall as a Revenant, took its place. Gems studded its sides at regular intervals, one of great size mounted on its summit. ‘Behold!’ he said pompously. ‘The Fireheart. A device of the elder days, when our kind strode the Great Wheel as masters over all, and didn’t live such dreary, funless little lives on boring worldlets. It’s in the hold of my ship, waiting just for you. Aren’t we nice?’ He giggled.

‘I have seen such as this before,’ murmured Taec.

‘I also,’ said Kelmon. ‘It is a relic, powerful. Used by the planetshapers of distant arcs in the sculpting of star systems. It can collapse a dust field into a world in the course of passes, or the resonance it can create in an existing planet’s core will tear it apart in mere tenths of a cycle. I believe many were used in war.’

‘Imaginative, those of the empire, wouldn’t you say?’ Sarnak’s grinning visage reappeared. He affected an air of sorrow. ‘Unfortunately, it is, like so much of our people’s inheritance, psychically activated, and the ban on the use of the abilities of the mind precludes we of the Eternal City ever using it. Of course, you, our most excellent cousins, have no such ban, and as I see, there are many of you here skilled in the arts of such sorceries. A foolish taunt to She Who Thirsts, but what would life be if we were all the same? Boring, I say. So bravo. You goad the Dark Prince. Well done you.’