Hearthpwn

Anyone know what interaction happens with Justicar Trueheart?

I'm pretty sure it would give you "tank up" as it is replacing your "starting Hero Power" with a better one. Or it may just do nothing. Very unlikely it will upgrade the hero power you get from Sulfuras.

Do you think a copy or two of Direhorn Hatchling or Ornery Direhorn could fit into this deck somehow? Because you know... Who doesn't like new cards? ;)

There is one Ornery Direhorn, but I agree that 2x Direhorn Hatchling is really good. I'm liking Ornery Direhorn quite a bit, but, as someone on reddit pointed out, if Blazecaller is all over the ladder, it might be a dead card unless you get Divine Shield, +3 Health, or +1/+1 (and even then, it's weakened enough for a strong value trade).

I like it, though, so I'll start by running 2x Ornery Direhorn because most Adapt pulls will have at least 1 good pick for it at that stage (especially since it won't show Taunt due to already having it, iirc).

What I question is actually Dirty Rat. It's great in today's meta, but with Reno decks going away and most quest rewards being in decks that run a nontrivial number of other minions, it doesn't feel as broken. 

I also an not sure if Primordial Drake is good enough at 8 mana. An 8 health taunt with a small damage AoE that late might not be impactful enough. You already curbstomp aggro/pirate decks, and 2 damage isn't going to clear midrange decks like elementals or jades. Maybe it helps against a post-Megafin murloc board? Just not sure what it does for this deck that isn't done better with King Mosh.

Wow if Adapt doesn't show taunt if the minion already has it then Ornery Direhorn is a little better than I thought.

The version I've theorycrafted is a Curator package with Primordial Drake, Direhorn Hatchling, King Mosh, and either Alexstrasza or Deathwing.