You kill the gate keeper to open the portals to past and future? This would change it? When you get both relics, I noticed the door you enter is open, the door closes when you enter & is closed when you spawn? I had hold of one relic was guarding the left portal when the conflux was up, and noticed (too late) that the door was open. Went to run to it, but as the conflux had been complete and Atheon was about to come out it closed again. I clipped it. (On Xbox one)