User blog comment:TheUnknown285/A very interesting image from the remake of Halo (yes, this is ME-related)/@comment-4888821-20120403003857/@comment-1655340-20120403213127

The Reapers are always aware of Those Who Came Before. . ..

The solar flare in Assassin's Creed that decimated the populace of Earth = Prothean battle in the Sol System, kinda like the asari goddess?

Ooh, third tie-in: the Halo Creed Effect.

... Yeah, I know, but one can imagine, right?

Anyways, @Firetiger: I'm pretty sure it was the Insunannon. They were the tentacled species that the statues on Ilod were of, they being there already when the protheans discovered the planet. Of course, they could've been even older than that, but I'm reasonably sure that's the species you're looking for.