Hmmmm? But a linear concept like time means nothing to the chaos gods. They've existed before they've existed before.

 They're certainly monsters at the level of the C'tan, probably even worse, though both are certainly lovecraftian to some degree(The chaos much less so and the C'tan moreso), still C'tan are many leagues lower then "lovecraft" in the eldritch category.

To be fair there's almost nothing quite like lovecraft fictionally.