As the universe took shape, so did a consciousnesses. A consciousness that soon took form and gained sentience. Lyria was born. She wasn't like any of the other gods, being born separate from them, in tern this makes her unique in a sense that she is not a god of any one specific idea or thing (Nature, luck, justice etc.) but the embodiment of existence itself. To put it simply, she is every reality that has, is and will ever exist. Events, choices, life, all that exist because she allows it. She knows all and sees all. Infinite in power and intelligence. Lyria rules reality in every way. The only thing that can exist even if Lyria wouldn't allow it are other gods for obvious reasons. Her power is drawn from the center of existence, the infinite cycle of renewing entropy that fuels the multiverse.
There's is nothing that could kill her due to her nature. Universes are born every second, this also explains the consequences of those who gaze upon her true form, for when she takes it, anyone of limited intelligence will go mad due to them not being able to comprehend what they would be witnessing. The sum of all the knowledge and infinite existences being crammed into their mind at once. She rarely if ever directly effects anything, simply letting the natural laws do their thong, but will switch things up to entertain her.