The Dark Wanderer


 * "A hooded stranger sits to play, holding a grim deck in his hands. Can you unravel the secrets surrounding this dark wanderer?"

 is a Tavern Brawl. It debuted January 4, 2017. For exact times, see the schedule.

Part of a multi-franchise event celebrating 20 years of Blizzard's  series, this Brawl features numerous special cards themed around those games. All games are played on the Whispers of the Old Gods battlefield, with the boss using the Secret Level card back awarded from the Brawl.

Overview
This single-player Brawl sees players battling the Dark Wanderer. Players use custom decks, while the boss uses a variety of special Diablo-themed cards. Each game starts with three of the Dark Wanderer's unique Secrets in place.

The ostensible goal of the Brawl is to defeat the Dark Wanderer. However, should the player reveal all of the Dark Wanderer's Secrets, the boss will transport them to the realm of The Cow King, where the fight will continue against this new boss. This is not necessary to win the Brawl, but can be considered a hidden objective, as hinted at in the Brawl's in-game description.

At the end of each match, the player is presented with a scoreboard detailing how many minions and bosses were killed and how many Secrets were revealed.

This Brawl does not award a card pack, but instead has a special reward: the unique "Secret Level" card back.

Secrets
Each game starts with three of these unique Secrets in play for the Dark Wanderer, chosen at random. Since they are not included in the boss's hand, only three are seen each match, providing a different starting point for each new match.

Although not mentioned, Visions of Fate has a dual effect: prevent lethal damage, and then heal the opponent to full Health.

While included in the game data, the following Secrets are not believed to be used in the Brawl. However, due to the random nature of the Brawl this is hard to confirm. If so, they likely represent earlier ideas for the boss's Secrets that were removed prior to release.
 * Missing

Opening the portal
If the player reveals all of the Dark Wanderer's Secrets, Enigmatic Portal is summoned on the boss's side of the board; if the board is full, it will directly replace one of the boss's other minions. At the start of the next turn, this casts Twisting Nether? followed by The Portal Opens, transporting the player to the Secret Cow Level (see below) and replacing their opponent with The Cow King. The previous hero's Hero Power is also replaced with So Many..., their deck with a special 45-card deck, and their hand with 3 x Hell Bovine; an additional Hell Bovine appears on their side of the battlefield.

However, if the Enigmatic Portal is destroyed before it is able to activated, nothing will happen and the player will not get to meet the Cow King during that round. This is highly unlikely, since the Enigmatic Portal is not considered a minion for most purposes, and is additionally Immune; but it can be targeted by random destroy effects such as Void Crusher, allowing it to be destroyed. This may be a bug.

Alternatively, if the last Secret consumed is Visions of the Necromancer, and the minion played is Sylvanas Windrunner, her Deathrattle will cause you to steal the Enigmatic Portal for yourself. As a result, when its effect activates, your hero, Hero Power, deck and hand will be replaced with those of The Cow King, and a Hell Bovine will be summoned for you; the match will then continue.

Significantly, both Twisting Nether? and The Portal Opens appear to be cast as one event: as a result, deaths from Twisting Nether? will not be resolved until after the hero has been replaced by The Cow King. As a result, if the player who controls the Enigmatic Portal has a full board when its effect activates, no Hell Bovine will be summoned. (The Hell Bovine's summoning happens when the hero is replaced, at which time the destroyed minions have not yet been removed.) Any Deathrattles and random minions generated from minions destroyed by the Twisting Nether? will also not be activated until after the hero has been replaced.

Random minions
These minions have a chance to spawn throughout the encounter when enemy minions are destroyed. The "gold" granted by Chest of Gold! is in fact 2 x The Coin.

Dark Wanderer
Each game starts with three of the Dark Wanderer's unique Secrets in place, chosen at random (see list).

The Cow King
The Cow King starts with 3 x Hell Bovine in his hand, and 1 x Hell Bovine in the battlefield.

Below is a partial decklist. The total number of cards in the starting deck is 45.

Strategy
The Dark Wanderer plays a lot of Warlock cards most of which are imp related (or actually imps) and Warlock spells, so keep that in mind when creating a deck. Having board clears such as Flamestrike or Hellfire really helps too since he will be playing a lot of minions and his Hero Power Diabolical Powers is "Summon a random imp." Sacrificial Pact is effective for healing since there is almost always an enemy imp in play.

When it comes to the Cow King, having board clear cards are also very helpful because he will be summoning a lot of Hell Bovines, depending on how long it takes to kill him.

If low on health it's a good idea to destroy the Discarded Armor to gain 5 Armor. Additionally, Chest of Gold! is advantageous to summon a high cost minion, and Weapon Rack will be available if a weapon is needed to destroy a minion with.

Reaching the Secret Cow Level
The Cow King can only be reached by activating all three of the Dark Wanderer's Secrets. This requires careful deckbuilding and deduction as to which Secrets the boss likely has in play that match. It will probably be a slow game, so take your time while deciding on your next move.

As a reminder, the boss's Secrets are chosen at random from the following possibilities (a visual list can be found above): There are two additional Secrets that are included in the game data but do not appear to ever be chosen by the Dark Wanderer: All of these except for the first three can be triggered only by the player summoning a minion with a specific ability (or Legendary rarity). Since this accounts for 7 of the 10 possible Secrets, it is wise to include a number of minions with these qualities, to test for and hopefully trigger the related Secret.
 * Visions of Fate
 * Visions of Hate
 * Visions of Knowledge
 * Visions of the Amazon
 * Visions of the Crusader
 * Visions of the Necromancer
 * Visions of the Sorcerer
 * Visions of Valor
 * Visions of the Assassin
 * Visions of the Barbarian

The other Secrets are triggered by game states. Visions of Knowledge is relatively easy to trigger: simply build up your hand to 9 cards. This is easiest with a control deck; ideally Handlock or similar. Both Visions of Hate and Visions of Fate require you to take damage, the latter requiring you to allow yourself to be defeated. Visions of Hate can often be triggered naturally while fighting the Dark Wanderer, especially if you allow the boss to get in a few hits. For Visions of Fate, it is best to assume the boss does not have this Secret: only if all other attempts to trigger the remaining Secret fail should the player then allow themselves to be killed, assuming this to be the Secret in question.

Aside from its trigger condition, each Secret also has its own consequence, which can often tip the balance of the match. With a little foresight these can be worked around, and potentially used to the player's advantage. Visions of Hate, Visions of the Crusader, Visions of the Necromancer and Visions of Valor are particularly potent.

Once the player has gotten into the rhythm of reaching the Secret Cow Level, the next step is to work on arriving there in as good a state as possible, allowing the player to rack up a good total of minions killed for the final scoreboard.

The Cow King
If the player steals control of the Enigmatic Portal before it activates, their hero will be replaced by The Cow King, including the below emotes, all of which produce an identical result.

Lore
Clearly set outside the realm of Hearthstone, this Brawl tells the story of an epic battle between the Dark Wanderer and the Cow King. The story appears to take place between the end of Diablo I and the start of Diablo II, although it is likely not intended to adhere too strictly to the events of the series.

The Dark Wanderer

 * From Diablo Wiki


 * The Dark Wanderer is the warrior from Diablo I'' who has been possessed by Diablo, the very demon he sought to contain within himself. After finally engaging Diablo in a duel in the depths of the hell beneath Tristram, the unnamed Warrior defeated and killed the Prime Evil. However, by this time he had been thoroughly corrupted by the demon's influence, and was led to believe the only way he could contain the Lord of Terror was by placing Diablo's foul soul within his own body, inserting the soulstone in his forehead.


 * ''Diablo I Ending


 * ''"The Soulstone burns with Hellfire as an eerie red glow blurs your vision. Fresh blood flows into your eyes, and you begin to hear the tormented whispers of the Damned. You have done what you knew must be done. The essence of Diablo is contained for now.


 * ''You pray that you have become strong enough to contain the Demon and keep him at bay. Although you have been fortified by your quest, you can still feel him, clawing his way up from the dark recesses of your soul.


 * ''Fighting to retain control, your thoughts turn toward the ancient, mystic lands of the Far East. Perhaps there, beyond the desolate wastes of Aranoch, you will find an answer.


 * ''Or, perhaps... salvation!"

The Cow King
The Cow King is the ruler of the Secret Cow Level, a secret level hidden within Diablo II.


 * From Diablo Wiki


 * The Secret Cow Level can be found in Diablo II'' (with or without the expansion). To create a portal to the secret level, combine Wirt's Leg and a Tome of Town Portal in the Horadric Cube while standing in the Rogue Encampment. A red portal will appear if the player has also killed the final boss on that difficulty. If playing classic, that means killing Diablo, but if the expansion is installed, the player will have to kill Baal before the portal can be opened.


 * ''The Secret Cow Level is a small area, full of Hell Bovines, bipedal cattle with polearms. A rather special cow, named The Cow King, always appears in the level. If someone kills the Cow King for the first time on the current difficulty, all players within the Cow Level will forever be unable to create another portal to the Secret Cow Level on the same difficulty again. They will still be able to enter the portal if another player creates it.


 * ''The cow level was the most popular place to level up in Patch 1.09, due to the huge numbers of cows and the fact that their slow speed, low resistances, and clumping behavior made them very easy to kill in bunches. The experience and item gains possible in the level were nerfed in Patch 1.10, and the level returned to its intended purpose as a novelty and a treat and not a place to endlessly exploit for massive experience gain.

The Secret Cow Level
The Secret Cow Level began life as a running joke from the original Diablo, but was later added to Diablo II, apparently in response to the popularity of the meme.


 * From


 * The "Secret Cow Level" is the result of a running joke from the original Diablo'' that spawned from an Internet rumor about the cows that appear in the game, seemingly without purpose. Supposedly, if the cow was clicked a certain number of times, a portal to a secret level would open. The rumor turned out to be a hoax, but the legend was born, and player after player asked Blizzard about how to access the level.


 * In Diablo: Hellfire, an add-on for Diablo created by third-party developer Synergistic Software, it was possible to change a parameter in a specific text file, so that the farmer was dressed in a cow suit, with appropriate new dialogue ("Moo." "I said Moo!"). To stop the rumors, Blizzard included a cheat in StarCraft that read "There is no cow level", adding to the official denial of the cow level. On April 1, 1999, a Diablo II Screenshot of the Week featured cows fighting. People wondered if the screenshot was an April Fool's joke or if there really was a Secret Cow Level planned for Diablo II'', which turned out to be true. The "Secret Cow Level" is considered one of gaming's top ten Easter eggs according to IGN.

The Secret Cow Level returned in reimagined form in Diablo III, by the name of "Whimsyshire". In order to enter Whimsyshire, players must first "craft the Staff of Herding, bring it to the skeletal remains of a cow along the Old Tristram Road, and speak with the Ghost of the Cow King."

Trivia

 * This is the second single-player Brawl (the first being Storming Stormwind), and the second to award a card back and/or not to award a card pack (the first being the Winter Veil Brawl Gift Exchange).
 * This Brawl is the first time Hearthstone has fully depicted elements from another Blizzard game, albeit within the confines of a Tavern Brawl. Previous cross-franchise influences have been limited to cryptic references in minion quotes and the occasional themed card back.
 * At the start of the Brawl, when the innkeeper attempts to introduce the Dark Wanderer, the boss interrupts, saying "Who am I? None of your business." This is a reference both to the hidden identity of the Wanderer (the demon lord Diablo, hidden in the body of the human warrior Aidan) and specifically to the summon quote of Mysterious Challenger.
 * The Dark Wanderer's Secrets use a unique 'Secret' image, both on the icon above the boss's picture, and when mousing over the cards.
 * The Secrets also use a different sound when they are triggered, which sounds like a cowbell rather than the normal Secret activation "cling" sound. This is likely a foreshadowing of the Secret Level (Phase 2) of the Brawl, and The Cow King.