Hearthpwn

She's in the wrong line-of-worc

This will be used in a ton of decks, but even though it's a very good card, nothing about it is busted, so I like it.  

I feel like, in exactly this set - following the year rotation - this card has a good amount of potential, particularly in Death Knight.
For Death Knight, your legendary selection will either be powerful class cards ( Due to the fact that Death Knight cards are inherently more powerful due to the rune mechanic ), or neutral legendaries - which, due to mini sets, tends to lean more towards big, expensive game winning cards. Neptulon the Tidehunter, The Jailer etc.

After the neural list gets powercrept a bit this cards value will diminish though.
Still awesome in Arena regardless!

I think the game would be better without discover. Just make this "add a random legendary to your hand". If you need discover, make all disover cards discover something that did not start in your hand. Then the strategy of anticipating what you opponent has can return. 

RiP Brightwing :(

"We're not friends now...."

We got alot of good 3 mana 3/4 for arena but this one could be one of the strongest

Thats just good value for stats. And potentially game-changing with a few legendaries.