Overview:

This Esper control/combo deck helmed by Y'shtola, Night's Blessed leverages high mana value noncreature spells to trigger her life-drain and card draw engine. The strategy focuses on enchanting Y'shtola with Curiosity or Ophidian Eye to create a "draw your deck" loop while draining opponents. Secondary win conditions include Aetherflux Reservoir, Exsanguinate, and Sheoldred, the Apocalypse, supported by stax elements (Mystic Remora, Trouble in Pairs) and a robust interaction suite. Y'shtola serves as the critical engine piece, enabling both card advantage and life manipulation.

Primer:

Core Strategy Execution:

1. Early Setup (Turns 1-3): Deploy mana rocks (Sol Ring, Arcane Signet), stax pieces (Mystic Remora, Esper Sentinel), and protect Y'shtola with Mithril Coat or Flawless Maneuver.
2. Engine Assembly (Turns 4-6): Cast Y'shtola and attach Curiosity/Ophidian Eye. Use counterspells (Force of Negation, Swan Song) to protect the combo.
3. Combo Execution: Cast 3+ MV noncreature spells (e.g., Windfall, Supreme Verdict, Dig Through Time) to trigger Y'shtola's damage/draw loop. Chain spells indefinitely with Displacer Kitten flickering rocks or Y'shtola to reset protection.
4. Win Conditions:
   • Drain via Y'shtola triggers and Aetherflux Reservoir.
   • Finish with Exsanguinate or Sheoldred, the Apocalypse after drawing most of the deck.
   • Generate infinite mana with Displacer Kitten + Sol Ring/Mana Vault (if present) to fuel X spells.

Mulligan Priorities:

• Keep hands with 2-3 lands, early ramp, and at least one protection/card draw engine.
• Prioritize hands with Curiosity effects, Y'shtola, and interaction.
• Avoid hands lacking blue/black mana or with only high-CMC spells.

Key Tips:

• Use Displacer Kitten to reset Mystic Remora’s cumulative upkeep or dodge removal.
• Teferi, Time Raveler enables instant-speed sorceries to trigger Y'shtola during opponents' turns.
• Phyrexian Reclamation and Sevinne's Reclamation recover key pieces.
• Bolas's Citadel allows free spell chains to accelerate the combo.

Weaknesses:

Critical

• Commander Dependency: Removing Y'shtola repeatedly cripples the primary engine.
• Enchantment Vulnerability: Losing Curiosity/Ophidian Eye stalls the combo.
• Anti-Draw Hate: Hullbreacher or Narset, Parter of Veils nullifies card advantage.

Moderate

• Graveyard Reliance: Recursion tools like Phyrexian Reclamation are vulnerable to exile effects.
• Artifact/Enchantment Removal: Aetherflux Reservoir and stax pieces are fragile.

Minor

• Slow Board Presence: Minimal creatures make early aggression challenging to block.
• Life Total Pressure: Bolas's Citadel and fetchlands risk self-damage.

Most Important Cards:

• Curiosity/(Combo engine with Y'shtola)
• Aetherflux Reservoir/(Primary win condition)
• Displacer Kitten/(Combo enabler, protection)
• Mystic Remora/(Early card advantage)
• Sheoldred, the Apocalypse/(Life drain, card advantage)
• Teferi, Time Raveler/(Control, combo flexibility)
• Force of Negation/(Free interaction)
• Smothering Tithe/(Mana acceleration)
• Bolas's Citadel/(Spell chain enabler)
• Exsanguinate/(Finisher)

Attribute Ratings:

Speed: 7/10
Can assemble the Curiosity/Y'shtola loop by turn 5-6 and win via Aetherflux/Exsanguinate shortly after.

Resilience: 6/10
Strong counterspell/protection suite but heavily reliant on Y'shtola staying alive.

Consistency: 8/10
Abundant tutors (Praetor's Grasp, Dig Through Time), card draw, and redundancy in combo pieces.

Interaction: 9/10
Exceptional removal (Deadly Rollick, Void Rend) and counterspells (Mana Drain, Fierce Guardianship).

Rating Justification:

This deck operates at cEDH-adjacent speed (T5-6 wins) with robust interaction and tutor density but lacks the ultra-fast mana and tiered combos of true cEDH. Its reliance on a commander-centric engine and vulnerability to removal place it in the high-power optimized range.

Power level: 7.0 - 7.5