Overview:

This five-color deck helmed by Omnath, Locus of All focuses on high-impact multicolor spells, cascade synergies, and explosive late-game plays. The strategy revolves around ramping into game-ending ultimatums (Ruinous Ultimatum, Eerie Ultimatum), massive X-spells (Debt to the Deathless, Crackle with Power), and cascade enablers like Maelstrom Wanderer. Omnath serves as a mana battery and value engine, enabling color-intensive spells while providing card selection. The deck also leverages "all colors" synergies with Leyline of the Guildpact and Iridian Maelstrom, while maintaining resilience through recursion (Muldrotha, the Gravetide, Auroral Procession).

Primer:

Core Strategy Execution:

1. Early Setup (Turns 1-4): Prioritize land ramp (Cultivate, Farseek, Rampant Growth) and mana fixing (Chromatic Lantern, The World Tree). Deploy value engines like Whirlwind of Thought or Prophet of Kruphix.
2. Midgame Power Plays (Turns 5-7): Cast Omnath to enable color-intensive spells. Use cascade triggers (Maelstrom Nexus, Maelstrom Wanderer) to cheat out threats like Ghalta and Mavren or End-Raze Forerunners.
3. Endgame (Turns 8+): Resolve ultimatums, X-spells, or Progenitus/Zacama, Primal Calamity as finishers. Recur key pieces with Eerie Ultimatum or Muldrotha.

Mulligan Priorities:

• Keep hands with 3+ lands including at least two colors.
• Prioritize early ramp/fixing (e.g., Sol Ring + Farseek).
• Avoid hands lacking colored mana sources for Omnath’s WUBRG cost.

Key Tips:

• Use Leyline of the Guildpact to enable Iridian Maelstrom as a one-sided board wipe.
• Wilderness Reclamation synergizes with Omnath’s end-step trigger and X-spells.
• Threefold Signal amplifies multicolor spells like Brokers Charm for replicated value.

Weaknesses:

Critical

• Extremely vulnerable to early aggression due to slow mana base (11 tapped lands) and midrange curve.
• Relies heavily on resolving 6+ CMC spells with minimal protection beyond Swiftfoot Boots.

Moderate

• Struggles against stax effects (Rule of Law, Blood Moon) that disrupt ramp and cascade.
• Limited graveyard hate beyond Bojuka Bog despite recursion reliance.

Minor

• Some anti-synergy between Notion Thief and the deck’s own draw engines.
• Spirit of Resistance requires perfect color diversity to function.

Most Important Cards:

• Maelstrom Wanderer (Cascade value engine)
• Ruinous Ultimatum (Board reset + win condition)
• Zacama, Primal Calamity (Mana sink + removal)
• The World Tree (Critical color fixing)
• Eerie Ultimatum (Recursion bomb)
• Wilderness Reclamation (Mana doubling enabler)
• Whirlwind of Thought (Draw engine for noncreature spells)
• Leyline of the Guildpact (Synergy cornerstone)
• Crackle with Power (Primary X-spell finisher)
• Prophet of Kruphix (Untap engine)

Attribute Ratings:

Speed: 5/10

• Capable of explosive T7-9 wins with ultimatums/X-spells but lacks early-game threats.

Resilience: 4/10

• Limited protection for key pieces; recovery relies on high-CMC recursion spells.

Consistency: 6/10

• Strong ramp package offsets five-color challenges, but lacks tutors for specific wincons.

Interaction: 5/10

• Spot removal suite (Void Rend, Path to Exile) is versatile but light on counterspells.

Rating Justification:

This deck operates as a classic battlecruiser build with powerful late-game plays but suffers from slow setup and vulnerability to disruption. Its ability to dominate in later turns aligns with casual-focused tiers, while its lack of fast combos or robust interaction prevents higher optimization.

Power level: 4.5 - 5.0