the whole thing was Kei's dream - I SERIOUSLY thought maybe...

...this was going to be the case!!

It was just too weird!! He sees his old friend again, then immediately after all this weird stuff keeps happening.

The Old Lady, was maybe an angel trying to direct him.

The aliens and maybe even Gantz himself too are demons.

Kinda like in the film Jacob's Ladder I guess, I really thought this was how it was gonna be in the end, maybe it would have been better if it wERE something like this!