Ok guys I flash in {white mane lion} to block a 2/2 then I block with a flyer with {augury owl}. I have to return a creature to my hand so does my owl still live if I return it to my hand. Thanks.
Your creature doesn't die since you return your creature to your hands the Attackers creature hit nothing since the blocker isn't there anymore
If I understand your situation, you can't block with both a creature on the field and the lion and bounce the other blocker to save it.
The time for fast effects comes either before or after you've declared blockers. You can't declare some blockers, cast an instant (or creature with flash) and declare more blockers.
You can either block with the owl, then flash in the lion to save it, or flash in the lion before blockers are declared and block with it.
Thanks bj didn't want to cheat my friend.