Question about the stack

[Bant]

Ok so this happened in a game and i didn't know what to do....

Scenario: My opponent has a 1/1 creature out with gigantiform on it, an enchantment aura that gives the creature 8/8 and trample.

On my turn I decide to Oblivion Ring creature with gigantiform, my opponent in response plays relic crush to destroy oblivion ring...

Would my Oblivion Ring resolve before the relic crush, exiling the creature thus removing the enchantment THEN destroying Oblivion ring, bringing that creature back...

OR

Would Oblivion ring be fizzled, leaving the enchantment and creature on the battlefield?

[Aspirations]

Oblivion ring resolves and enters play, thus exiling the creature. With the creature gone, gigantiform has nothing to be attached to, thus it goes into the graveyard. It's the same as if you were to destroy the creature. The enchantments go into the graveyard.

Then relic crush resolves, destroying oblivion ring, and returning his 1/1 creature to the field.

Oblivion ring would have to resolve in order for Relic Crush to even target it.

<stack 1>
Oblivion Ring
</stack 1>

<stack 2>
Relic Crush
</stack 2>

[Arix]

Be very careful about "in response". If the situation happened as you described it, not only would Gigantiform fall off, but the creature would be exiled forever.