User blog comment:Martolives/Mass Relays/@comment-2079715-20120402103043

While playing ME3, on each playthrough I wondered same thing. Legion has a line in ME2 that explains much in ME universe. Before him, Sovereign said it, though less clearly. Mass relays were created by US, the Reapers. Your civilization was built on OUR technology, and thus we have set you on a path that WE desire. Legion states that Geth strive to build themselves, BY themselves. That's why they fought Heretics in first place. And than, we see Legion ready to take Reaper tech to advance the Geth in ME3. Arrival of the Reapers is also a mystery! A small codex entry in Secondary tab says that Reapers can enter Galaxy without using relays. That they can employ FTL speed on their own. So WHY the fuck did they need Sovereign in ME1 to open the Cidatel portal?