Overview:

This mono-black Rat tribal deck helmed by Karumonix, the Rat King focuses on swarming the board with toxic Rats to proliferate poison counters while leveraging sacrifice synergies and combo potential. The commander enables card advantage through Rat tutoring and amplifies the poison strategy via universal toxic 1. Secondary win conditions include Marrow-Gnawer + Thornbite Staff infinite token generation (enabling Blood Artist drains or Phyrexian Altar mana for Torment of Hailfire), Thrumming Stone-fueled Relentless Rats cascades, and Wound Reflection/Phyresis Outbreak finishers. Karumonix is critical for maintaining Rat density but can be re-cast cheaply due to low CMC.

Primer:

Core Strategy Execution:

1. Early Setup (T1-3): Deploy mana accelerants (Sol Ring, Chrome Mox, Dark Ritual) and key Rats like Lord Skitter, Sewer King or Piper of the Swarm. Use Herald's Horn/Jet Medallion to reduce Rat costs.
2. Midgame Swarm (T4-6): Cast Karumonix to refill with Rats, then flood the board with Relentless Rats (enhanced by Thrumming Stone ripple triggers). Deploy Ashcoat of the Shadow Swarm for exponential power boosts and graveyard recursion.
3. Win Conditions:
   • Poison: Overwhelm with toxic Rats, proliferate via Karn's Bastion, and amplify with Ichor Rats/Vraska's Fall.
   • Combo: Marrow-Gnawer + Thornbite Staff creates infinite Rats; sacrifice to Phyrexian Altar for infinite mana into Torment of Hailfire or Blood Artist triggers.
   • Overrun: Door of Destinies or Ashcoat buffs enable lethal combat.

Mulligan Priorities:

• Keep hands with 2-3 lands, at least one Rat, and ramp (Sol Ring, Dark Ritual).
• Prioritize Thrumming Stone, Herald's Horn, or Phyrexian Altar in slower metas.
• Avoid hands lacking early Rats or mana acceleration.

Key Tips:

• Use Urborg, Tomb of Yawgmoth + Filth for unblockable Rats.
• Sacrifice Rats to Razaketh, the Foulblooded or Diabolic Intent to tutor combo pieces.
• Protect Grave Pact/Dictate of Erebos with Imp's Mischief to lock opponents out of creatures.
• Yawgmoth's Will enables explosive recursion of Rats and combo spells.

Weaknesses:

Critical

• Board wipes (Blasphemous Act, Damnation) devastate Rat density and reset poison progress.
• Graveyard hate (Rest in Peace) disrupts Phyrexian Reclamation, Revenge of the Rats, and Ashcoat recursion.
• Anti-token tech (Cursed Totem, Torpor Orb) shuts down Marrow-Gnawer and Piper of the Swarm.

Moderate

• Artifact removal targets critical pieces like Phyrexian Altar, Thrumming Stone, and Door of Destinies.
• Life gain strategies delay poison victories.

Minor

• Limited flyer defense, though deathtouch Rats from Ogre Slumlord help.

Most Important Cards:

• Marrow-Gnawer (Infinite Rat engine with Thornbite Staff)
• Thrumming Stone (Enables Relentless Rats cascade)
• Phyrexian Altar (Mana generation/combo payoff)
• Relentless Rats (Primary swarm engine)
• Karumonix, the Rat King (Toxic enabler & card advantage)
• Thornbite Staff (Combo piece with Marrow-Gnawer)
• Grave Pact (Creature lockdown)
• Demonic Tutor/Vampiric Tutor (Consistency for combos)
• Torment of Hailfire (Mana sink finisher)
• Wound Reflection (Life loss amplifier)

Attribute Ratings:

Speed: 6/10

• Can threaten T5-7 wins via poison or combos but lacks fast mana beyond Dark Ritual.

Resilience: 5/10

• Vulnerable to wipes and targeted hate, but recursion (Phyrexian Reclamation, Ashcoat) provides some recovery.

Consistency: 8/10

• 18x Relentless Rats, 7 tutors, and Karumonix’s card selection ensure reliable access to key pieces.

Interaction: 5/10

• Limited to spot removal (Snuff Out, Infernal Grasp) and Withering Boon; relies more on board control via Grave Pact.

Rating Justification:

This deck demonstrates focused synergy with multiple paths to victory and high consistency, but its reliance on creature swarms and vulnerable combos caps its speed and resilience. It operates optimally in T6-8 windows, aligning with the Focused tier.

Power level: 6.0 - 6.5