Leo takes a good look at the newcomer for a first time. He's really not sure what to make of him, but the man seemed direct enough. Best to keep an eye on him for now, and that arm looks strong.
"Grohg was it? My name is Leo. How about you stay by me, we'll face the threats of this place together. Stay alert, not every danger in this place has the courtesy of shaking a weapon openly."
Grohg listens to Leo, falls in step next to him, and says "Aye" to what he said. He thinks to himself, "Why would the enemy shake weapons at me? Must be ritual here. Is courtesy to do this. I will shake my weapons now before battle." Then he looks at Leo, "Thank you for advice Leo. I will be courteous fighter."
The party returns to the room where they found the gem and were exposed to the poison gas. How do you approach the room, who opens the door, etc?
"Zinna, that ghost hand thing you do? Think you can use it to open the door?"
"If so, I suggest we move further up the hall, use that to crack open and then immediately shut the door. If a notable amount of gas comes out in that short time frame, we can just leave."
Out of Character: Mage hand has an implied force limit of 10 pounds. More than enough for a typical door, but probably insufficient for one with bad hinges.