Mirror of Hsssthak

Eons before the rise of elves, humans and dwarves, the reptilian lizard-kind ruled the world. Powerful mages and strong warriors, they strode the land as demigods, but their seers knew that the time would come when even their civilisation would fall. To avoid the loss of all they had worked for, the seers scryed forward past the devastation that would end their race, then past the time it would take for new life to arise. They realised that lizard-kind would rise again, although stunted and debased, bestial compared to the dizzying heights of their current reptilian civilisation. It was to these distant descendants that they would gift their power and their ability to sculpt life and magic, in the hope that they would overcome their base beginnings and allow reptilian society to rise again.
The reptilians decided that they could not simply package up their knowledge and power in the hope that it would be found by their descendants at the right time. One of their strongest sorceror-kings volunteered to be mummified and entombed for the many millennia it would take for the conditions to be right for lizard-kind to rise and rule once again.
A temple-tomb was carved out deep underground in a propitious location, and the sorceror-king Hsssthak was mummified while still alive, his soul bound to his desiccated remains. The tomb was stocked with everything he might need, and guardian skeletons set to patiently watch and destroy intruders that may disturb Hsssthak's sleep - including an animated tyrannosaurus rex skeleton in the charnel pit. Once the preparations were complete, the temple was sealed and the air within changed to an inert gas, before Hsssthak entered his long sleep.
Knowing that Hsssthak would need a way to check on the outside world from the confines of his preservation throne, on the wall opposite him was mounted an immense scrying mirror, able to be controlled by the user resting their hand on the control gem mounted in the armrest of the throne. It was the most powerful and advanced scrying mirror ever designed, and would not be surpassed with the passing of the ages. With the mirror, Hsssthak was able to watch and listen to the outside world between his long periods of torpor, learning of the rise of the hairless apes and the crude tongues they jabbered and shrieked at one another. When a group of the apes invaded his tomb through a gap in the defences caused by a long-ago earthquake, he was prepared.
Hsssthak was able to follow their progress through his mirror, directing the temple servitors to test them, until finally the humans reached his still-sealed inner sanctum. When they breached the seal, the reptilian sorceror-king was waiting to offer them a deal; in exchange for the wizard of the party agreeing to swear a Geas to take the magical scrolls etched upon sheets of gold and crystal to the shaman of the nearby lizard-man tribe, Hsssthak would gift the party the great wealth within his tomb, and allow the wizard to learn certain of his spells.
The wizard agreed, swearing the great magical oath, and Hsssthak allowed the passage of so many eons to catch up to him, decaying his form to fine dust in moments. All that was left was the contents of his tomb - and the immense scrying mirror, mounted on the wall opposite his throne, awaiting its next user.