Saving Throws are listed under Proficiencies in every class entry. Multi-classing would be pretty overpowered if you could pick up saving throws that way considering there is a feat that grants your proficiency on a single ability score (as well as a +1 to the Attribute).
As far as I know, neither Mearls or Crawford ever answered the explicit question. Oh wait, Crawford did.
Vials - Attack: [roll0], Damage: [roll1] + [roll2] (Chaos: [roll3])
Brue - Attacked the Death Dog and missed
Death Dog - Attacked Brue and Greycastle, but missed both.
Greycastle - Attacks and hits the Death Dog
"All you had to do was get me the damned mushrooms!" the gnome cursed in his madness. Vials changed targets and fired another sickly green ray at Greycastle. The ray struck the paladin squarely; he grunted in pain.
Character Sheet Update: Brue has the Great Weapon Fighting Style.
Roll damage dice individually (in Brue's case, roll the two 1d6 individually. If your weapon damage dice come up as a 1 or 2, you can re-roll those dice.
[section]Brue growled in frustration and swung at the two-headed dog in front of her. She would have Vials, or die trying.[/section]
[roll0] and [roll1] and [roll2]
OOC:
What are the walls down here made of? Stone? The floor?
Vials - Attacked w/Disadvantage: [roll0] [roll1], Damage: [roll2] + [roll3] (Chaos: [roll4] [roll5])
Brue - Attacked Death Dog and missed
Death Dog - Death Dog bit Greycastle, but missed Brue
Greycastle - Used Reaction to Protect Brue, Struck dog and delivered it a divine smite
Vials matched Brue's growl of frustration, his pet clearly not performing to expectations. Calling upon his magic again, he conjured another ray of sickly green light and launched it at Brue. It was well aimed and would have struck had Greycastle not interposed his shield and deflected the attack at the last second.
[section]Brue focused intently on the death dog and swung a second time. As she swung, the stone walls and floor of the cottage basement began to sing to her; she could feel the stonework in her marrow, and it beckoned.[/section]
OOC:
[roll0] with greatsword for [roll1] and [roll2]
Question: Merge with stone. Does it merely allow Brue to walk across stonework floors as per the pass without trace spell (granting +10 to Stealth), or does it permit Brue to physically meld into the stone wall/floor, walk through the stonework, and pop out on the opposite side of Vials? I'm guessing the former because the latter would be mega powerful for a racial ability.
Your attack rolls have been unbelievable, and not in a good way.
Merge with Stone is only Pass Without Trace, per the Elemental Evil Player's Companion.
Also, you haven't asked, but Brue could probably climb on top of that stone table to get to Vials next round. It's a little too short for her to really get under effectively. If you want to try that, roll a Strength (Athletics) DC 14 Check. If you make it, you can treat it as difficult terrain. If you fail, you have to spend an action to get on top of it. If you roll a 1, you fall prone.