Hearthpwn

Okay, this boss starts out with a 3/8 scepter that can attack on his first turn, and he has a 5/5 with a deathrattle that does 5 damage to you that costs 3 mana.  A lot of the time, he coins this thing out on turn 2, and then drops another one turn 3.  That's not fair.  So we're not going to play fair either.

The great thing about Adventure mode decks is that they don't need to work consistently, they just need to work once. And that means that Adventure mode is a great place to bust out the cards that are powerful in certain circumstances, but aren't consistent enough to work in competitive play.  Cards like Astral Communion.

What I've done here is taken an Astral Communion deck, stripped out all the stuff you put into that deck for the games where you don't draw Astral Communion, and then stuffed it to the gills with huge cards.  This deck needs to Innervate into Astral Communion on turn 2, or else you should concede. 

But when you get the Innervate+Astral opening, this boss will have no way to break through your taunts, you can stabilize from his early onslaught with tree of life, and then you can control the board, control the staff, and beat his stupid face in.

If you're missing any of these legendaries, just throw in Force Tank Max, or giants, or any other big legendaries you happen to have.