Inside her head

You are moved to new world, but you are not exactly a person now...You are just a voice, or rather a spirit, located in a head of certain female adventurer. She keeps her consciousness and is aware of your presence, but she definitely isn't happy because of having unwanted guest inside her brain! You process everything faster than her, so you can help her act accordingly. You can make her dodge better and faster, you can help her aim her skills, you can detect dangers that she can't see, you can enhance her natural senses and skills... You are her personal upgrade, sort of! You can hear what she hears, you can see what she sees, you can feel what she feels... but what now? You get used to this situation and become some sort of partners or maybe she will do everything in her power to get rid of you!? Step into this wild story and observe pure chaos!