It's a pity that this was such a short one-shot. I was enjoying it.
Your grammar and storytelling are good, especially in the beggining.

I was gonna say that Halibel’s insecurity and awkwardness in front of Aizen is very uncharacteristic of her but then I remembered how she babbled his name in chapter 375.

Like I said, it's a shame that this wasn't longer. I think you could have developed more this idea, telling us more about her life as an Espada. Maybe even her feelings during the battle in Karakura.

How sad! ;;

She sees him as god. Now who does that remind me of?