Hearthpwn

 I will add a more detailed explanation when I am more proficient with this deck.

This is a midrange paladin deck that combines minions that persist on the board with efficient buff cards and Cult Master to fuel the deck. This allows you to either combo them with Baron Rivendare, Equality or with Avenge. You should always have a target for buffs with this deck. Your opponent's should have a hard time dealing with all the deathrattles.

Mulligan

You should be muliganning for any minion 3 or less with the exception of the Aldor Peacekeeper. He could/should be kept if you are fighting a class where he'd be really useful around turn 3. So maybe against a druid, definitely against a handlock, possibly against a paladin, and maybe against a priest. Since most of these classes make tempo plays around those turns and countering some of that tempo is really important. Against most other classes he would likely be a dead card. I also tend to throw back my Knife Juggler in favor of some more deathrattle minions if my hand is already good.

Naxx Changes

I have done some card changes to the deck in preparation for Naxx. Some aren't out yet, but here is the changelog in case you want to construct the deck before these cards are made available.

-2 Blessing of Kings +2 Avenge. Blessing of Kings just felt really clunky even with all the targets. I felt like it slowed me down too much. A 1 mana cost buff is much more flexible.

-2 Nerubian Egg +2 Undertaker. There just weren't that many activators for the egg; it felt really clunky. Also after I took out Blessing of Kings for Avenge I only had 1 targetable activator which is really bad.

-2 Nerub'ar Weblord +2 Dancing Swords. I made this change because I feel that the meta will shift away from more battlecries even without the use of the Nerub'ar Weblord, and that Dancing Swords also draws you a card with Divine Favor. It also has a better synergy with the Undertaker, and it strengthens your turn 3 which is important with a turn 4 Truesilver Champion. I am still iterating on this change though.

-2 Dancing Swords +2 Loot Hoarders. A lot of the time the cards gained from the Dancing Swords didn't help me out regarding Divine Favor. Making this change allows me to have no bad deathrattles for Baron Rivendare, and another 2 drop to feed the Undertaker.

-1 Divine Favor +1 Cult Master. The Cult Master should be an effective draw engine in this deck with all the tokens and our hero power. Divine Favor just hasn't been working out as I initially expected and I think this change is much better since this deck is based around board control, so you will be getting cards for trades you would've been making in the first place. Much more flexible than Divine Favor, and it's a 4/2 body. I am debating on whether or not to replace the last Divine Favor with something more consistent like an Acolyte of Pain which should work well in this deck with the Aldor Peacekeepers and all the buffs.

-1 Baron Rivendare -2 Loot Hoarder -1 Undertaker +2 Mad Scientist +1 Repentance +1 Redemption. Baron Rivendare just didn't really help me out. As much as I like him in this deck, I think there are better options. I removed the Loot Hoarders in favor of the Mad Scientists because they are functionally similar except that you know what you are going to get with the Mad Scientist, and you don't have to pay mana for the card. I have removed one Undertaker and Baron Rivendare to give the Mad Scientist more cards to pull from.

-1 Blessing of Might -1 Repentance -1 Divine Favor +2 Scarlet Crusaders + 1 Redemption. In order to make the deck more consistent if I end up drawing into my secrets I have added the Scarlet Crusaders and Redemption. I have also switched out a Blessing of Might because of the removal of Divine Favor.

-1 Blessing of Might +1 Undertaker. Blessing of Might just didn't really fit the deck. The deck has now been renamed to Deathrattle Paladin from Deathrattle Buff Paladin because of this. I'm still unsure if Undertaker is the best replacement.

-1 Scarlet Crusader +1 Kel'Thuzad. I just wasn't really feeling the Scarlet Crusaders so one was taken out.

-1 Scarlet Crusader -2 Redemption +1 Baron Rivendare +2 Repentance. I just didn't like Redemption and Scarlet Crusaders in the deck. While Redemption did fit the theme of the deck, I felt like Repentance would be better overall, especially in the end game and with Kel'Thuzad, Baron Rivendare, and the Cult Master in the deck.

-2 Repentance +2 Redemption. I feel like this change is better in all matchups whereas the Repentance isn't that useful against things like zoo. I really liked Repentance in the control matchups where it would deal upwards of 5 damage, but it is not that useful against aggro decks.