You rush forward to grab at it's testicles, and find it very easy to do so. With the creature trying to keep Sia between you and it, it's testicles are right there for you. You grab the monster's nuts and start roasting them with a 15 ft cone of fire.
[The result of this attack has been deemed too graphic and under the context of sexual gore. As such, we will be skipping to the aftermath.]
With the creature dead, you run over to Sia whom is lying on the ground in pain. Unfortunately, she was just too close to avoid all of the fire that was mere inches from her dedicates. She'll likely need healing, but the act definitely sobered her up enough to not be under the fog's influence for a moment. That just leaves the last troglodyte that's been having it's way with Linan. Having seen the truly horrifying things that you are willing to do, it tries to remove Linan and run. Linan, however, is still under the effects of the mist and refuses to let go of the troglodyte. Unable to remove her, it simply tries to run while she continues to fuck it. You can see a trail of cum as it tries to waddle away.
Spoiler (click to show/hide):
Troglodyte Dex save with disadvantage: 6
Burning hands: 13