Hearthpwn

It started with 3 Paladin Quests and the problem that I pretty much faced only Mill druids on my way to the pack. After a few games of fooling around how to win against those druids, I think I found the perfect deck.

With the charge property of Stonetusk Boar, you can attack immediately before the druid Naturalizes or kills it with his Coldlight Oracle. Furthermore the Druid draws all cards for us, so we have an (almost) never ending supply of Boars and Buffs, where Blessing of Might is a cheap buff for the boars and Abusive Sergeant creates minions to buff in the next round or draw additional cards when naturalized.
Worked on NA and EU so far. Also beat a few other decks.
Disclaimer: This deck comes out short against lots of other decks. It is really just a reaction on all the Mills out there. For example you don't stand a real chance against Discard Warlocks.

Update 16/09/16:
I hope all the downvotes are from Mill Druid Players ;)
A few words on strategy.
Some Mill Druids tend to shoot directly from turn 1 like Innervate, Coldlight, Innervate, Innervate, Coldlight, Naturalize (on one of their own Oracles).
With moves like this, your hand is full - and full of Power. You can directly strike back with a buffed boar.
Just look out for a few things. The fewer minions there are on your side of the board, the fewer targets there are for his Naturalize. That means, if the Druid wants to burn more cards, he has to kill his own minions. But this reducuces his damage potential.
On the other hand we don't want to have too many cards in hand, because we would overdraw too much.
So, you have to find a balance between those two states, which is not too hard. Therefore the best combo is always Boar+Blessing because it deals lots of damage while only providing one target for the Druid.
Always try to keep one Boar in hand to deliver a final blow on about turn 5. Until this turn just try to deal some damage without filling your board completely. Should be an easy win, then.
Also, never play a minion on turn 1. It will get naturalized immediately and gives the Druid an advantage. Instead, just wait, because so he has to kill his own Oracles in order to let you (over)draw.
Mulligan.
Losing against Mill only occurs if you run out of Boars, so mulligan for as many as possible. In case you get too many, just get rid of some on the first turns and stock up your buff cards.

Have fun crushing Mill Druids :D

K.