I don't really comprehend how Nishi knows so many things. He has showed he's not that skillful and strong in the missions, got killed by a weak 'Tanakense' in the second mission and is always playing sneaky and coward. As far as we know he had 90 points before he died, he also knew Izumi from past battles where he prob got that 90 points so I don't think he has completed the 100 point game even once. But he knows so much about Gantz, I wonder if he knew that much already when this manga started and didn't want to share with Kei & Kato at the beginning apart from some small info. He also stated that catastrophe thing in his blog, wonder how he got that info back then and if that already had happened in past occasions. I'm not really understanding how the different phases work (1&2) and what makes it to be so.
Something is noticeable is that now they're visible to the normal people, the enemies are stronger and there's no time limit.
In another note, I like to see the bond btwn Kei and Kato and I hope we can see a bit of developing of it ( I really thought it was not really highlighted before Kato died, so I hope it does now). In the other hand I expected a warming feeling btwn Reika and Kurono. Tbh I expected her to give him a big hug and confess herself once again. :( I like her character so much.
So looks we're getting into the ending game, I wonder how is the catastrophe going to unfold. 7 days remaining to that happening. So probably this will be the last "mission"?