Overview:

This Grixis deck is built around The Twelfth Doctor and Vislor Turlough, leveraging a swarm strategy with 24 copies of Relentless Rats. The Doctor’s "demonstrate" ability amplifies spells cast from exile or graveyard (e.g., via Underworld Breach or Thrumming Stone), creating token copies of Rats and scaling their power exponentially. Vislor Turlough provides card draw at the cost of life loss, while the deck employs group-draw effects like Howling Mine to fuel its engine. Win conditions include overwhelming combat with massive Rats, Warstorm Surge triggers, and Peer Pressure theft. The strategy leans heavily on synergistic chaos effects like Possibility Storm and recursion tools to maintain momentum.

Primer:

Core Strategy Execution:

1. Early Setup (Turns 1-4): Deploy mana rocks (Sol Ring, Arcane Signet, Talismans) and group-draw engines (Howling Mine, Scrawling Crawler). Cast Vislor Turlough early to offset the deck’s high card velocity.
2. Rat Swarm (Turns 3-6): Cast Relentless Rats from hand, leveraging Thrumming Stone’s ripple 4 to chain additional Rats from the deck. Use The Twelfth Doctor to copy Rats cast from exile/graveyard (e.g., via Underworld Breach or Eruth, Tormented Prophet), creating tokens and buffing the Doctor.
3. Win Conditions (Turns 5-8):
   • Combat: Overrun with Rats (each Rat’s power scales with their count). Use Archetype of Imagination to bypass blockers.
   • Burn: Trigger Warstorm Surge or Delayed Blast Fireball (cast from exile for 5 damage per opponent) for direct damage.
   • Theft: Peer Pressure to steal opponents’ creatures if you have the most Rats.
4. Recursion/Protection: Recur Rats via Underworld Breach or Eldrazi Monument (grants indestructible but requires sacrifice fodder).

Mulligan Priorities:

• Prioritize hands with 2-3 lands (including black sources for Rats), a mana rock, and at least 1-2 Relentless Rats.
• Keep hands with Thrumming Stone, Underworld Breach, or Warstorm Surge if other pieces are present.
• Avoid hands lacking black mana or early plays.

Key Tips:

• Use Vislor Turlough’s goad ability to deflect aggression. Sacrifice him before your end step to avoid life loss from his draw effect.
• Peer Pressure can steal entire creature types if you dominate Rat counts.
• Possibility Storm disrupts opponents but can also cheat your high-impact spells (e.g., Eldrazi Monument).
• Wishclaw Talisman tutors critical pieces but plan for its transfer to an opponent.

Weaknesses:

Critical

• Board wipes (e.g., Wrath of God) annihilate the Rat swarm with minimal recovery tools.
• Graveyard hate (Rest in Peace) shuts down Underworld Breach and recursion lines.
• Anti-token strategies (Torpor Orb, Elesh Norn, Grand Cenobite) neutralize Rat synergies.

Moderate

• Artifact removal targeting Thrumming Stone, Eldrazi Monument, or mana rocks slows the deck significantly.
• Hand size punishment (Nekusar, the Mindrazer) synergizes dangerously with Vislor Turlough’s life loss.

Minor

• Color-fixing issues due to heavy black requirements and limited dual lands.
• Life total pressure from Vislor Turlough and pain lands.

Most Important Cards:

• Relentless Rats (Primary win condition, scales exponentially)
• Thrumming Stone (Enables mass Rat deployment via ripple 4)
• Underworld Breach (Recurs Rats and key spells from graveyard)
• Eldrazi Monument (Protects Rats and grants evasion)
• Warstorm Surge (Alternate win condition via Rat ETBs)
• Peer Pressure (Theft enabler in Rat-heavy boards)
• The Twelfth Doctor (Copies Rats, buffs itself, enables demonstrate)
• Possibility Storm (Disrupts opponents, cheats high-CMC spells)
• Vislor Turlough (Card draw engine despite life loss)
• Howling Mine (Fuels draw for Vislor and opponents)

Attribute Ratings:

Speed: 6/10

• Can threaten wins via Thrumming Stone ripple chains or Warstorm Surge by turns 5-7, but reliant on setup.

Resilience: 4/10

• Minimal protection against wipes/graveyard hate; recovery depends on Breach or Monument.

Consistency: 7/10

• High Rat density and ripple synergies ensure frequent access to threats, but tutors are limited.

Interaction: 3/10

• Light on removal (only Chaos Warp, Crosis's Charm, Counterspell) and no stax to slow opponents.

Rating Justification:

This deck has a focused Relentless Rats strategy with explosive potential via Thrumming Stone and Underworld Breach, but its fragility to common disruption and slow setup place it in the Casual/Focused tier. Speed aligns with T7-8 wins, but resilience issues cap its ceiling.

Power level: 4.0 - 5.0