First of all, it seems necessary to clear up the misunderstanding about Kyle and "?".
So-called "? END/Another Time End" was added as anomalistic irregular bonus.
That was a kind of "afterword" written in a conversational format. In that scenario there was no meaning to supplement main story.
That was a story in higher realities/dimensions and metafiction. That is not connected to main story time-sequentially.
Therefore that is not canon. Main story of VLR ends in the hiding place of Crash Keys on April 13 in 2029.
When young Sigma saw the explosion through the window. That's the ending as canon of VLR.
...
It goes without saying that what is the identity of "?". It's as many players are presuming.
At least, I wrote "Another Time End" in VLR with the intention of it. Also there is no doubt that "?" intervened in ZTD.
In order to imply that, the ability of Mind Hack by Delta was set to resemble the things that "?" can do.
You can choose one you like from the following 3 theories. The character did it or Delta did it or "?" did it. The choice is yours
In passing, I'd tell you about Kyle. I said that "Another Time End" was metafiction.
Therefore I'd like you to interpret Old Akane's words in "Another Time End" as metafiction.
This means that she was talking toward the player in this REAL WORLD.
She said "He (Kyle) has arrived at December 25th, 2028." And now is 2016. This year isn't 2028. This is my plan.
I'm often asked like "Where is Kyle?" The short answer is this. "He will be in 2028." I hope this is useful for you. Thank you!
Quelle