Questline Dude Paladin

Have had an awful lot of fun (and reasonable success, with a 60% win rate over ~ 30/40 games) piloting this deck since the start of the expansion. There is nothing quite like slapping the hero-power for two behemoth Silver Hand recruits every turn to really burn through your opponent's morale.

Mulligan

First Day of School is the ideal follow-up to the quest on turn two, often supplying all three of the one-drops needed to progress the quest. Knight of Anointment and Peasant similarly advance the quest, although their inclusion here is justified by their ability to refill your hand (with the former reliably providing outs such as Equality or Hand of A'dal). Peasant's presence on the board is particularly threatened by the hero-powers of DH, Druid, and Rogue, and so recycling it should be considered in the absence of Righteous Protector in these matchups. Immediately mulligan it against any Mage deck.

Stonehearth Vindicator is another consideration here due to its sheer value generation, as are the rest of the one-drops in the interest of quest progression. 

How do you win?

Value. I refuse to elaborate on this.