Karlach, Tiefling BerserkerHow it works & interactions with other cards

Understanding the Specialize Mechanic

Specialize is an activated ability that allows you to pay a cost and discard a card to transform Karlach into a new version based on the discarded card's color. Karlach, Tiefling Berserker is unique because she can specialize even while in the graveyard. When she specializes from the graveyard, her triggered ability returns her directly to the battlefield with a perpetual 'can't block' modifier, making her a persistent offensive threat.

Resolution and Triggers

The specialization process happens in distinct steps. First, the specialize ability is activated by paying mana and discarding a card. Once the ability resolves, Karlach transforms into one of her five specialized forms. If this happens while she is in the graveyard, her first triggered ability puts her onto the battlefield. Simultaneously, the specific 'When this card specializes' ability of the chosen form (such as drawing cards or buffing creatures) goes on the stack and requires targets if applicable.

Perpetual Effects and Blocking

A common mistake is forgetting the 'perpetual' nature of her graveyard return. If Karlach specializes from the graveyard, she can never block again for the rest of the game, even if she moves to other zones and returns later. However, she retains her first strike and haste, ensuring she remains a potent attacker. Note that specializing from the hand or battlefield does not apply this restriction.

Timing Your Specialization

You should generally specialize Karlach when you need to bypass a stalled board or recover from a board wipe. Specializing into Karlach, Tiefling Punisher is excellent for card advantage, while Karlach, Tiefling Spellrager can provide a massive tempo swing by casting a free spell from your library.

Interaction examples

Value from the Graveyard

Karlach, Tiefling PunisherSolemn Simulacrum

If Karlach, Tiefling Berserker is in your graveyard, you can activate her specialize ability by discarding a Black card. She transforms into Karlach, Tiefling Punisher and enters the battlefield. You then trigger her ability to sacrifice a creature; by sacrificing Solemn Simulacrum, you draw one card from the Golem's death trigger and two cards from Karlach's specialization trigger, while each opponent loses 2 life.

Doubling the Impact

Karlach, Tiefling GuardianRoaming Throne

With Roaming Throne on the battlefield naming 'Tiefling', you specialize Karlach into Karlach, Tiefling Guardian. Because Roaming Throne doubles triggered abilities of the chosen type, the specialization trigger fires twice. You can now target another creature you control to give it +8/+8 total (+4/+4 from each trigger) until end of turn.

Free Spells and Aggression

Karlach, Tiefling SpellragerKarlach, Tiefling Zealot

When you specialize into Karlach, Tiefling Spellrager, you immediately seek an instant or sorcery with mana value 3 or less and can cast it for free. This is often followed by a turn where you use Karlach, Tiefling Zealot to create a 2/2 Knight and give your entire board +1/+1 and haste, ensuring your newly specialized Tiefling can attack immediately if she didn't already have haste.