Muv-Luv Unlimited

With Kasumi so attached to the floating brain, it almost definitely belongs to the Takeru of this world. The current Taku’s transfer to this world was likely due to something Yuuko did, possibly using the brain. The fact that Yuuko accepted Takeru’s claims, had him enlisted as a cadet, and even gave him high-level security clearance suggests that she knows a lot more about how he came to this world than she reveals.

Kasumi is tricky... She is definitely Sumika in some form, given the name anagram, desire to wake Takeru up, and her attachment to the brain. My guess is that she is the Sumika of this world, but she mentally broke down after Takeru’s death. Yuuko had her name changed and erased Sumika in whatever records she has access to, possibly alongside Takeru, for the purposes of this experiment. Kasumi recognizes that this Takeru can never replace her childhood friend, but he still reminds her of him and she starts to open up to him.

The Takeru death would have to be at a point before the other squad mates got together, since there seems to some kind of convergence of human interactions, but none of the squad mates recognized Takeru (nor did they know Sumika). Maybe Meiya did not even meet Takeru in the past? Or did she forget Takeru’s name? Tsukuyomi certainly seems to recognize Takeru’s name, but maybe she only looked him up after he joined the squad.

Why is Mikoto female? I’m not sure. It’s really fishy that so many other characters match very well, especially considering that this world deviated from at least as far back as WWII. Like I said, there seems to be some kind of convergence, where people seem to meet the same people as they would in other worlds, reproduce the same offspring, and so on. For Mikoto, my guess is that he/she is a hermaphrodite, where he lived as a make in Takeru’s world, but as a female in this BETA world. Mikoto’s ending does not indicate this (unless it was on the skipped H-scene), so my guess is that her male parts were surgically removed.

The biggest mystery is Alternative IV. It clearly involves parallel worlds, since Yuuko used Takeru’s transfer as evidence of the theory. But I’m not entirely sure how she plans to use this to save humanity. Are they trying to invade another world? Try to find some world to dump the BETA into? Find people like Takeru from other worlds to expand their manpower? Worth noting her success in summoning Takeru does not imply that she can send anything away from this world to another world, especially if the brain was necessary for the summon. Maybe this was the challenge that led to Alternative IV being abandoned at the end? None of my ideas here seem very plausible...

What are the BETA anyway? It’s interesting that they apparently don’t exist in Takeru’s world. If Urobuchi wrote this, then the BETA are actually humans. Maybe they came from yet another world? Or maybe their victims become BETA? I think there’s very little I can deduce about the BETA from Unlimited alone.