If I use Maternal Instinct in my turn, my opponent enhance with Lord of the Makai Commit: If this attack deals damage, get a card from your momentum to your hand. My attack deal damage, I choose to resolve Maternal Instinct's effect as the 1st floating effect, did I opponent still have a chance to pull back a card from their momentum B4 I head to my End Phase with Maternal Instinct's effect?

nope. They also could not partial block (or block a throw) and then reversal.

stamp. moving to the end phase basically shuts off anything that was waiting to resolve.