It's this one, after she give you a drink, you then have to drink it to gain futa. But it's temporary so you have to drink more until it's permanent so you have to have a bit of health to do it until the player say it's permanent.
This hot spring, or you can get up top of the main base with that Voice lived in that has a hot spring too. You do have gem? Right, use it to remove certain parts.
