Who arrived on Genesis/Domain before Blue Team?

This thread contains spoilers in regards to Halo 5: Guardians plot

Spartans
After following and listening to the hidden intel located on the Genesis related missions and mission 14 “The Breaking” It seems like a certain someone has documented their arrival on the installation Genesis and then the Domain there on after. He mentions that “she” is hunting him down, of which I assume is Cortana. He also mentions that she has control over the guardians…etc

So who do you think this “guy” is?

He is a forerunner. He preserved his essence (basically a digital imprint) and tried to reach “Bastion” (unclear if thats a person, place or AI) through the domain. But when the Halos fired and the Domain fractured he ended up on Genesis.

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> He is a forerunner. He preserved his essence (basically a digital imprint) and tried to reach “Bastion” (unclear if thats a person, place or AI) through the domain. But when the Halos fired and the Domain fractured he ended up on Genesis.

I could be wrong but I believe “Bastion” was a location on Delta Halo. So what purpose do his audio logs serve to the plot of Halo 5? He speaks about Ancilla ( forerunner A.I ) and even the Guardians. He even implies that he may of taken down the Warden at a certain point in time. Everything is very unclear.