An obvious direction to go, would be since she is a demon, she just decided to freshen up her looks a bit.
Because staring at the same face in the mirror can get boring.
Perhaps have an amazingly hot celebrity on TV catch the MC's attention enough that Abere decides that her look would be Aberes new look, with a couple of tweaks, like breast size, eye and hair color, and also height.
That leaves an opening for a short backstory of how she had gotten the human looks that she had been using.
And it allows you to experiment, as she tries different looks, if you want.
Also, since you have said that you are going to keep the game going, you could get away with centering an entire update on the time that Abere is trying on different looks.
My vote is for any with red hair, nice boobs, great ass, and maybe throw some fangs in there, to spice things up.
Although, horns do make great handles, so that would work too...