What happens if a creature is returned to owner's hand after blocking or being targetted?

Question

What will happen to a creature if it's been killed either after being targetted by spells or by blocking?

example 1: Player A casts Chandra's Outrage targeting Angelic Wall; Player B uses Crystal Shard's ability (return target creature to its owner's hand) to return Angelic Wall to his hand. Does Player A's spell still resolve and find new targets? And if Player B has no other creatures and Player A has the only creatures in play, would it target one of Player A's creatures?

Also, if Player B waited for Chandra's Outrage to resolve and the Angelic Wall dies, when Player B uses the Crystal Shard ability on Angelic Wall before it goes into graveyard will it take effect? Will Angelic Wall be returned to Player B's hand rather than going to the graveyard?

example 2: Player A attacks with a 3/3 creature and Player B blocks with a creature that's only a 2/2 and then lets damage resolve. When Player B uses Crystal Shard's ability, will his 2/2 creature be returned to his hand instead of going to his graveyard? And if Player B declared that his 2/2 will block Player A's creature, then used the Crystal Shard ability before damage resolves, does Player B's creature still block Player A's creature, or would Player A's creature get through because damage hasn't resolved yet?

Answer 1

Example 1:

If a spell with targets would resolve, and if it has no targets left, than that spell will be countered.

This is known as fizzle-ing

*note if the spell still has at least 1 target, it will still resolve. chandra's outrage only targets a creature, and therefore will be countered, but flames of the firebrand will not be, if it still has at least 1 target left.

Example 1':

no, player B would not be able to target the wall if it dies. It will be put into the graveyard as a state-based effect before anyone gets priority to cast spells or activate abilities.

Example 2:

You can activate crystal shard after blockers have been declared and before combat damage is dealt. the 2/2 will return to your hand, and the 3/3 will still be considered blocked

Once combat damage is dealt it's too late. the 2/2 will go to the graveyard as a state-based effect before anyone gets priority to cast spells or activate abilities.