Ok, never mind. I thought the dragon would be Huge, not gargantuan. You can grapple an enemy one size larger than yourself, and Terrus can become Large. At level 9, he can become Huge, and therefore could grapple the dragon, but right now that’s out.
Now, with Mastery of Force, he could still do it telekinetically, but then it’s a Str Saving Throw, and the DC is only 13 or 14, though he can boost that a little. But with no disadvantage, I’m not willing to do that.
It would be a satisfying end, though I wonder what the dragon would do if we just left. I can’t imagine it would just sit there. Terrus can try to get the Node, staying behind to trap the dragon.
Maybe we should just bolt. Auraia can get the staff. Her There and Back Again Ability lets her teleport at the beginning of her turn, do an action, then teleport back. No chance of the dragon grabbing the staff mid flight, that way.