Overview:

This Grixis (UBR) deck leverages Lord Xander, the Collector as a disruptive engine, combining mill, discard, and sacrifice effects to dismantle opponents' resources. The primary strategy revolves around fast mana acceleration to deploy high-impact spells early, utilizing Underworld Breach combos with Lion's Eye Diamond and Brain Freeze for instant wins or Thassa's Oracle as a finisher. Secondary paths include explosive mill synergies with Bruvac the Grandiloquent and Syr Konrad, the Grim, alongside reanimation for value. Lord Xander amplifies disruption but isn't essential to the core combo win; he serves as a potent stax piece that pressures hands, libraries, and boards, though his 7-mana cost makes him vulnerable to tax. The deck operates at cEDH speeds, prioritizing efficient tutors and protection to execute compact wins.

Primer:

Core Strategy Execution:

1. Acceleration & Setup (Turns 1-2): Deploy fast mana (e.g., Mox Diamond, Lion's Eye Diamond, Dark Ritual) to generate explosive starts. Use tutors (Demonic Tutor, Vampiric Tutor) to fetch combo pieces or key disruption like Opposition Agent.
2. Disruption/Combo Assembly (Turns 2-4): Cast Ad Nauseam or Peer into the Abyss to draw extensively, or deploy stax elements (Ashiok, Dream Render, Dress Down). Assemble Underworld Breach + Lion's Eye Diamond + Brain Freeze to mill opponents out or enable Thassa's Oracle. Alternatively, use Bruvac the Grandiloquent with kicked Maddening Cacophony for instant-kill mill.
3. Win Execution (Turns 3-5):
   • Combo: Activate Breach, sacrifice LED for UUU, cast Brain Freeze targeting yourself to fuel Breach escape, then loop to mill opponents or win with Thoracle.
   • Mill: Attack with Lord Xander (doubled by Bruvac) or cast Fractured Sanity with Syr Konrad to burn opponents.
   • Reanimation: Cheat threats like Consecrated Sphinx or Tergrid, God of Fright via Reanimate.

Mulligan Priorities:

• Keep hands with 1-2 lands, fast mana (≥1 piece), and a tutor/combo piece (Breach, LED, Thoracle).
• Prioritize protection (Force of Will, Fierce Guardianship) if expecting interaction.
• Avoid slow hands without acceleration or tutors.

Key Tips:

• Breach Flexibility: Use Breach to recur tutors/interaction if combos are disrupted.
• Life Management: Leverage Treasonous Ogre and Ancient Tomb cautiously; Ad Nauseam risks life loss with high-CMC cards.
• Stax Timing: Deploy Opposition Agent or Ashiok, Dream Render to disrupt opponents' fetchlands/tutors.
• Thoracle Backup: Peer into the Abyss + Thoracle wins if Breach is exiled.

Weaknesses:

Critical

• Graveyard hate (e.g., Rest in Peace) cripples Breach, reanimation, and Syr Konrad.
• Anti-artifact stax (Null Rod, Collector Ouphe) shuts off fast mana and LED combos.
• Commander tax severely hinders recasting Lord Xander (9+ mana).

Moderate

• Rule of Law effects limit combo turns and tutor chains.
• Aggressive decks pressure life totals, complicating Ad Nauseam/Treasonous Ogre.

Minor

• Limited board wipes; relies on Cyclonic Rift for mass removal.
• Flyers can bypass Lord Xander's defense.

Most Important Cards:

• Underworld Breach (Combo engine enabling recursion and loops)
• Lion's Eye Diamond (Primary mana source for Breach combos)
• Thassa's Oracle (Compact win condition)
• Brain Freeze (Combo mill piece and storm enabler)
• Demonic Tutor (Fetches any win piece or answer)
• Ad Nauseam (Draws most of the deck; fuels wins)
• Peer into the Abyss (Draw engine and Thoracle setup)
• Mox Diamond (Critical fast mana for early acceleration)
• Force of Will (Free interaction to protect combos)
• Bruvac the Grandiloquent (Doubles mill for instant-kills)

Attribute Ratings:

Speed: 9/10

• Capable of T1-2 wins with perfect draws (e.g., land, LED, Breach, Brain Freeze) and consistent T3-4 wins via tutors and fast mana.

Resilience: 7/10

• Robust protection (free counterspells, Deflecting Swat) and recursion (Breach) mitigate disruption, but graveyard reliance creates a critical vulnerability.

Consistency: 9/10

• 10+ tutors and extensive draw (Ad Nauseam, Peer) ensure reliable access to combo pieces; low average CMC enhances Ad Nauseam efficacy.

Interaction: 8/10

• Efficient counterspells (Fierce Guardianship, Pact of Negation), targeted removal (Rakdos Charm), and stax (Opposition Agent) disrupt opponents while safeguarding wins.

Rating Justification:

This deck operates at cEDH-tier speed with T1-4 win potential, leveraging efficient combos, exhaustive tutors, and free interaction, aligning with Tier 1 cEDH benchmarks. However, its graveyard dependency and vulnerability to specific stax prevent it from reaching Tier 0's near-unbreakable consistency.

Power level: 9.0 - 9.5