Intro:

I have had a lot of fun pushing with this deck from Diamond 5 to Legend over the span of 24 hours with a 57% winrate. So, I thought I could share my list with the general strategies and mulligans involved as well as possible replacements. UPDATE: Just finished on the Wild Leaderboard for June 2020 at rank 176 exclusively using this deck with a 65% win rate! (I'm also testing cutting a Micro Mummy for Crystalsmith Kangor for Odd DH and Pirate Warrior.)

What's the general strategy?

This deck is at its core a midrange deck, which means the most successful strategy for winning games is to fight for the board. Of course, fighting for the board is no problem for this deck through sticky early game minions such as Righteous Protector; Shielded Minibot; and Shotbot, then securing your board through buffs such as Hand of A'dal; Blessing of Kings; and Annoy-o-Module, and finishing the game with board and resource reloads such as Call to Arms; Mysterious Challenger; Lightforged Crusader; and Murgurgle Prime.

General Mulligan Tips (UPDATED):

-Always Good Keeps: Righteous Protector; Shielded Minibot; and Shotbot are great plays for the first two turns.

-Always Good Keeps Going Second: Hand of A'dal; Micro Mummy; Lightforged Zealot; as well as the cards mentioned above. 

-Never keep secrets, Mysterious Challenger will be disappointed in you if you do. UPDATE: More experience with this deck has taught me keeping Redemption going first with a two-drop in hand is a powerful play and probably the only situation in which to keep a secret. Mysterious Challenger can forgive this.

 Mulligan and Strategy per Class (UPDATED):

Demon Hunter - Warrior - Paladin: Demon Hunter and Warrior are the two most popular classes on the Wild ladder from my experience, and are nearly always their aggro variants with Odd Demon Hunter and Pirate Warrior. Paladin is also usually Mech Handbuff Paladin or some other aggro archetype. The strategy against all three classes is the same: get onto the board immediately and keep your opponent off of it. As long as you deal with their early minions, you should be able to develop a wide and resilient enough board to take the lead. Mulligan aggressively for Righteous Protector and a two drop when going first and for two two-drops when going second (don't keep Micro Mummy or Hand of A'dal without another minion to support them), but don't mulligan away Righteous Protector when going second as it can help your curve on turn three.

Warlock - Shaman: Warlock and Shaman's most popular archetypes of Cubelock and Big Shaman put a timer against you before they take the board for themselves and keep you off of it. The strategy here is to stick early game minions; buff them; and send them face. Mulligan for your Righteous Protector and two-drops as always, but if you are going second or already have an early game minion in hand, keeping one Blessing of Kings; Annoy-o-Module; or Lightforged Zealot will help continue the pressure. For Discardlock and Even Shaman, I would keep the mulligan the same, but change the strategy to keeping your opponent off the board.

Priest - Druid: Priest and Druid's most popular archetypes of Raza Priest and Jade Druid (or some Combo Druid) play to stall and draw until they achieve their specific win condition. It will be difficult to pressure them down quickly with the sheer life gain both classes possess. The strategy here is to curve out and mostly hit the face. Only take trades when it helps defend a higher power (attack) threat on board, or if there is a high priority minion on board like Brann Bronzebeard or Archmage Vargoth. Mulligan for the usual generally good early game minions, but keeping one copy of Lightforged Zealot; Call to Arms; and/or Mysterious Challenger will help you curve out. I wouldn't keep the four-cost buff cards as you might not have anything to buff with these classes having good removal options. Also, be careful to not have too many minions on board for a potential Spreading Plague and, against Priest, Psychic Scream can break your Lightforged Zealot and Lightforged Crusader if you leave any neutral minions on their side of the board.

Mage - Hunter - Rogue: These three classes' most popular archetypes of Secret Mage; Even Hunter; and Odd Rogue play for continued tempo. The strategy here is to curve out and fight for board. Mulligan similar to that of against Priest and Druid. The only aspect that changes from those two class matchups is that you aren't trying to send your minions to the face as much.

Deck Replacements (UPDATED):

- Some versions of this deck include a more wide board supporting package of cards including Competitive Spirit; Never Surrender!; Muster for Battle; and Sunkeeper Tarim to replace the more single buff oriented cards such as Blessing of Kings, Annoy-o-Module, and the more situational secret of Hidden Wisdom. The wide board support package can be present more damage than the single buff package, but is also less consistent as it requires more cards to play and set up.

- Hidden Wisdom isn't a vital secret to play, but I like having the partial reload to help find my power cards. Could easily be replaced with Competitive Spirit or Never Surrender!. I wouldn't recommend Repentance; Eye for an Eye; Sacred Trial; or Getaway Kodo as these secrets are either too situational to trigger; not suited for the current Wild meta; or are more value-driven than tempo-driven.

-Micro Mummy can be replaced if you are tight on dust. I think the next best replacement would be Selfless Hero. If you find yourself facing a lot of Odd Demon Hunter and/or Pirate Warrior, Crystalsmith Kangor could be a worthwhile replacement as I am testing him right now, but only if you already have him or can afford to craft him.