Extremely weird. There's something there but it isn't alive and it isn't tangible and it isn't entirely there.

It is also supremely unconcerned by these shields, probably for the same reason it's unconcerned by walls and unaffected by arrows. 

Fazil does his thirty-foot healing spell for some reason.

Okay what is he even supposed to do about a creature that can ignore not just physical barriers but also magical shields - does a levinbolt do anything to it at all? 

...Ohhh. "Is that an undead dragon?"

It's hard to tell if a levinbolt does anything! 

"Yes," he says, and does it again. 

The dragon swoops into them and suddenly everything is staggeringly exhausting, in a way that leaves bone-deep weariness behind like they've aged sixty years and it's remarkable they're still on their feet at all -

Fazil does the healing thing yet again and then that is a little bit better though not all the way better. 

He has switched to magic arrows which at least seem to leave some painful-looking streaks in the creature as they pass through it.

Vanyel is pretty used to fighting while experiencing bone-deep exhaustion. He watches Hagan's arrows with mage-sight, in case there's a magical attack there that he can quickly replicate. 

"Energy attacks work though only about half of the energy gets through," Mahdi says, carefully aiming a fireball so that it will hopefully catch the ghost dragon and otherwise by stopped by Vanyel's shields from catching them. 

Then Vanyel can try some levinbolts at higher power, also carefully aimed to not risk hitting any of them or anything in the still-unexplored room full of potentially valuable treasures. 

These seem to do more to disrupt the vague formations of energy that seem to cling together as the dragon. It snarls noiselessly and sweeps around to pass through them again. 

He can partially undo that damage again.

He's very, very tired, but he's fought while more tired than this before, and there's a node still within reach. How does the dragon feel about a levinbolt five times more powerful than the last one? 

Bad! The dragon-form collapses, a bit, tries to pull itself back together - 

Ohgods he's so tired but he can hit it again - it's only about 80% as powerful as the last one, due to the tired–

It collapses more. Arrows streak through it. Fazil blasts them all, again - "that's the last of those -"

- and it's gone. 

"Lesser Restoration," he says dully, tapping Vanyel and sitting down.

He's still somewhat tired, sitting down is a good plan, but he's no longer utterly exhausted. 

"Does your healing spell also hurt it, because of the part where it's undead?" 

"Yes. Positive energy disrupts undead. Ghost of the dragon. We should absolutely have seen that coming."

"The actual, mummified dragon is guarding his tomb, reportedly, in the Veinstone Pyramid. I bet you have to kill it to get the ghost gone for good."

"- ghosts come back, if you haven't addressed their complaint," he says for Vanyel's benefit.

"Huh - that's a folklore thing about ghosts in my world, but I've never actually interacted with ghosts back home and I'm not sure how it'd work, magically speaking." 

"The thing that creates the ghost is a - shape their spirit leaves when it departs the world, and the negative energy will coalesce back into that shape. Eventually, not for days, we can finish clearing out the place in peace."

"We should do something to keep it from getting into the crystal ball room, if we're going to want to keep using that."

"Are there any kinds of shields that'll hold it off?" 

"I can consecrate the area. That won't necessarily keep it out but it'll weaken it considerably if it does decide to enter. I'd have to do it every day for a while to make it permanent, though. I assume one of the protections on the door must've been keeping it in, maybe we can replicate those?"

"Maybe! I got a decent look at most of them and can poke more now - oh, and it's not necessarily one I cut, if it wasn't an alarm or a trap, it might work again once the door is closed. I can try closing the door and see if there's any visible functional magic on it?" 

"Yeah, let's start by trying that." And they can drag themselves clear of the door.