Luckily you can use your Acrobatics to try to escape, I believe.
The problem if Tazskan teleport's both him and Mari back to the castle, with the mask. Is that they would both be out of action on the ground, temporary, assuming that the battle, it is still confined to underground?
However, if the battle was still underground, would still need a way to get back down, that would mean Tazskan using up both 4th level slots for round trip. (He has only two 4th level).
Would prefer not to use them all up before facing a dragon. But in the end depends on the initiative order, and so fighting may prevent all of that from happening.
The castle is not in range of Dimension Door. However, you could use it to shunt yourself to the surface and out of the range of your foes for the moment.
Oh, and in response to Mari's query, the group has been warned a few times that the masks do the will of their maker, Tiamat. At best, it wouldn't help an enemy. More likely, it would try to harm her.
Edited: daishain on 21st Jun, 2018 - 1:01pm
Daishain, I assume since Velon took damage I should mark down a spell slot for Shield having been used (But still failed vs one attack)? Hopefully it helped with any AoO, at least.
When you say Zarra is down again, do you mean prone or 0HP? I believe it's the former?
Is there space in here near the barracks where it widens out and we could fight the weretiger..thing?
Keep the shield spell use, only the last hit would have struck your normal AC, and it would still hit with shield.
Zarra is prone with the dragon on top of her. She used her shapeshifting to assume the form of a dire tiger. Which is pretty much a sabertooth tiger based on the description.
And yes, there is space here. The main tunnels are large enough to accommodate a full size dragon after all.