Mide and Dayan are their own distant ancestors, though to be fair there's probably some mingling among the Xaela tribes. Hey, at least it's better than that episode of Futurama where Fry goes back in time and becomes his own direct grandfather...
Breaking it down, there are no less than three time loops involving Alexander. I'm going to put them in chronological order from our perspective, though to be fair you can put the first as the last and vice versa.
The first surrounds his conceptualization.
1. Alexander returns Mide and Dayan to the distant past with Roundrox Codex fragment and the idea of him, and they found the Hotgo tribe and live out their lives. The idea is passed down in the tribe until near past Mide and Dayan work with the other Auri treasure hunters and assemble Alexander.
2. The events of the Alexander raid play out.
3. Mide throws herself into Alexander's core to shut him down, and Roundrox gives Schrodinger her Codex fragment who returns it to within Alexander, leading to 1.
The second surrounds his summoning 3 years ago.
1. The Illuminati summon Alexander after we defeat the Knights of the Round. A1 through A9 play out.
2. When we go to rescue Roundrox, she engages Alexander's time warp mechanism in her delirium, sending us three years into the past. Standing on top of Alexander, Schrodinger knocks Backrix' journal chronicling the events surrounding Alexander up through A10 out of his hands to the ground and tumbles down with it. The Illuminati kill the other Auri treasure hunters, Dayan is absorbed by Alexander, Mide seals Alexander in the lake, the Enigma Codex is shattered, and Quickthinx acquires Backrix' prophetic journal and adopts Schrodinger as his pet (renaming her "Shanoa").
3. With Backrix' journal as a guide, Quickthinx has the Illuminati summon Alexander in 1 above, leading to 2.
The last is the smallest and least intricate - it's how Alexander passed judgment on us.
1. Quickthinx traps us in a suspended time bubble and has Alexander pass Judgment on us. We're unfrozen at the last moment and survive.
2. We engage Alexander Prime in the Soul of the Creator and prove ourselves worthy, surviving Divine Judgment.
3. We go into the past and save our past selves from Alexander's Judgment in 1 above. Otherwise we've failed 2, and if we don't go save our past selves it creates a temporal paradox.
The latter two loops are nested in the first, but it is all ultimately one big loop. Nothing we did really changed anything, because the events of Alexander already happened and replay infinitely in a temporal loop. We couldn't change anything because then the circumstances setting up the events of Alexander wouldn't play out and it would create a temporal paradox like with "Judgment Loop 3" above.
Try not to think about it too hard. It'll just hurt your brain.