Azathoth is the greatest of the outer gods. All of existence itself(excluding Agrobarick) will be destroyed when he awakens. This existence includes Yog Sothoth is the embodiment of existence. Azathoth's powers are immeasurable.
He is the Omniverse itself and is omnipresent within it. His form can shapeshift into whatever it wants and is indestructible(the concept of destruction only exists in his mind.
Azathoth is likely one of the most strongest character in fiction. The only one equivalent to him is Yahweh in his true form.