Lets be honest here, Who wouldn't have picked #1? As bad-ass as Kurono is at times, His goal from the very beginning has been to survive. Why endanger himself further? He knows that he's leaving behind a successful and competent team, capable of defending themselves and reviving others, and now he has Tae to live for. It would be Irresponsible NOT to try to leave, as It would be putting his love for battle above his love for Tae. Kurono will return to Gantz, even if it takes as long as it did for Katou to return, but for now we get an interesting look at New-Kurono post Gantz.
A man said to the universe: \"Sir I exist!\"
\"However,\" replied the universe, \"The fact has not created in me a sense of obligation.\"
-- Stephen Crane