Aid of Thalos the mighty

Upon holding this artifact up in the sky and calling the words "I call upon Thalos the mighty!" then a spirit of a silver dragon materializes and goes after the turn of the summoner when hp is reduced to 0 the spirit leaves and the artifact is now worthless. to recharge the party must undergo a 10 hour long ritual where they venture to the upmost peak of the mountains where they set the artifact, then on the 2 adjacent pillars they must put a star Sapphire on one and a moonstone on the other. then when the clock strikes 12 a cleric must hold the charged gems the artifact and 2500 GP and hold them together then utter the words 

“By silver light and patient stars,
Guardian of frost and sky, hear me.
Let truth be my compass,
Let mercy guide my hand,
And by your watching heavens,
Be renewed.”

weight: 5 kg

GP value: 2500