- It's an interesting WMG, but considering how almost every shot the Mimics fire on the many many Normandy beach landings hits a target I personally feels that the assault on the Louvre by J-Squad is the first and only time it occurs. The Mimics just had their equivalent of AA guns surrounding what was their only real weakness. This is why it took them so long to attack the downed dropship - if they had known it was coming they could have blown it out of the sky long before it reached Paris. The Mimics are just so inherently lethal even without using the time control ability that the assault on the Louvre was effectively a suicide mission with little chance of success.
- Also remember how Cage said that he had never attacked the Louvre before when discussing it with J squad.
- Cage only remembers the loops that end with him dying. He doesn't remember the loops that end with an Alpha dying.
- This might be canon, considering Cage's statement when they get attacked over Paris: "they knew we were coming!"
- More likely it just makes sense that the Omega was expecting them after it felt Cage discover its hiding place using the link device? After all, the human who has been plotting against it all this time has just found it- what would it be expecting them to do if not attack immediately?
- Or, alternatively, it sent it back to before things started going wrong for the Omega, namely before the Major got sucked into the war. Perhaps both the Omega and the Major's deaths were responsible for this reset however it does leave open the possibility that the Omega left Earth in order to get re-enforcements to deal with an enemy that can steal it's time reset power.
- Or it buggered off to go fight/raid something/someone that can't steal its time-manipulation power. Good for humanity, bad for the rest of the galaxy.
All along, he's been helping the aliens. He fired dr. Carter when it became apparent he'd figured out too much of the aliens, and even a potential weakness. He fired him on the spot, and put his device (which he officially dismissed as useless) in a safe only he could access. He'd been warned about Rita and Cage by his mimic overlords, and had put guards on the ready to take them out on the way back. Their orders were to capture the two alive, and give Cage a blood transfusion (given how little he was bleeding, the actual injury he'd sustained would probably not merit a blood transfusion.)
So what actually changed his mind in this loop? It wasn't Cage's speech to him. Rather, it was because Rita off-handedly mentioned that they usually end up killing the general if he doesn't cooperate. If he'd gone along with the alien plan, it would have ended without the day looping, meaning he'd be permanently killed. If he gave Rita and Cage the device, he'd survive, but they'd still be captured, and the rest of the plan would go off without a hitch. That's also the reason the Omega knows that Rita and Cage are coming: The general told them that Cage had used the device.
Note also that the mimics are fighting almost flawlessly in the battle of Normandy, and everyone around Cage is receiving targeted attacks aimed to eliminate them, Cage somehow stays untouched and even the alpha doesn't notice him until it's too late, as if he's not yet been accounted for. The reason: Because the General is in contact with the Omega, and the Omega's actions are variable throughout the loops, so are the General's. The General knows about the fact the aliens will slaughter everyone involved in the offensive, so that's why there's iterations of the day where he pulls the trick with Cage (if he didn't know Cage would certainly die at Normandy, that move would have been career suicide). Cage doesn't usually end up fighting on the beaches of Normandy. It's just bad luck for the mimics that one of the few times he did, he got sprayed by Alpha blood.
- Perhaps the reason General Brigham is on their side is that in the past he also encountered an Omega, destroyed it, and was infected by the creature's consciousness, now working with the General's human memories and inteligence. That would mean... that Cage in the end is another human infected with Omega working for possible forthcoming aliens.
The answer to all of these questions: It was never about killing humans. It was about giving such a resounding show of supremacy that the humans wouldn't dare refuse their demands. The mimics are clearly some kind of mechanical creature. If they're artificial (probably the most likely, given how difficult it'd be for an immobile Omega to eat all the materials necessary to breed such creatures), a reasonable limitation by their creators design would be preventing the mimics from making more of themselves. That's why they want the humans. They've discovered that the humans have very similar mental structures compared to the mimics' creators (which is the reason why the alpha/omega blood works for humans), and wanted to use them to get around these restrictions. The humans would probably refuse (in fact, given the time reset, it's entirely possible the mimics tried the friendly approach first), which is why the mimics are trying to provoke a show of force to establish their absolute superiority.
This explains why Omegas provide time resurrection to others, but not to themselves.