if clark ever lost kara would it destroy him sinse she is all he has from krypton. i feel without kara clark is truly alone.
If she died peacefully or sacrificed herself to save the world I think he would be fine - if not proud in the latter scenario.
If she was killed by one of his enemies and he couldn't stop it - then ya, he would be pretty broken for awhile imo.
New52 Kara and Clark aren't really that close, so I doubt it would be as devestating as losing her pre52. I hope they regain that familial relationship like they had then, I really enjoyed seeing Clark as the protective older-brother type guy. But Kara has spent the last 23 issues of her book in denial and has yet to accept Earth as her new home.