Overview:

This Mardu (RWB) deck helmed by Kelsien, the Plague focuses on deathtouch synergies and experience counter accumulation to dominate the board. Kelsien serves as the central engine, using equipment like Basilisk Collar and Thornbite Staff to repeatedly ping and eliminate creatures, generating experience counters to scale his power. Secondary strategies include treasure generation via Revel in Riches and Mari, the Killing Quill, token swarms with Otharri, Suns' Glory, and alternate win conditions like Vorpal Sword. The deck relies heavily on Kelsien’s board control to enable incremental advantages and eventual victory through combat or combo-like finishes.

Primer:

Core Strategy Execution:

1. Early Setup (Turns 1-4):
   • Deploy mana rocks (Sol Ring, Arcane Signet) and equipment tutors (Stoneforge Mystic, Steelshaper's Gift) to fetch key pieces like Basilisk Collar or Lightning Greaves.
   • Cast Kelsien as early as Turn 3 with protection (Swiftfoot Boots, Mother of Runes).
   • Use targeted removal (Swords to Plowshares, Path to Exile) to clear early threats.

2. Midgame Control (Turns 4-7):

   • Equip Kelsien with deathtouch enablers to turn his ability into one-sided board wipes. Activate Thornbite Staff for repeatable untaps on creature deaths.
   • Generate value via Morbid Opportunist, Esper Sentinel, and Mari, the Killing Quill to maintain card advantage.
   • Deploy secondary threats like Otharri, Suns' Glory or Minthara, Merciless Soul to diversify pressure.

3. Win Condition Execution (Turns 6+):

   • Combat: Swing with a massive Kelsien (amplified by experience counters) or token armies from Otharri.
   • Combo: Use Thornbite Staff + deathtouch-equipped Kelsien to clear all opposing creatures, then attack freely.
   • Alt Wins: Activate Revel in Riches with 10+ treasures or Vorpal Sword’s game-ending ability.

Mulligan Priorities:

• Keep hands with 2-3 lands (including color-fixing), an early ramp/tutor, and at least one equipment or protection piece.
• Prioritize hands with Kelsien + protection (e.g., Giver of Runes, Loran's Escape) or key tutors.
• Avoid slow hands with only high-cost cards or no board interaction.

Key Tips:

• Use Boros Charm or Gift of Doom to protect Kelsien during critical turns.
• Drumbellower enables Kelsien to ping during opponents’ turns for surprise removal.
• Unfinished Business can resurrect Kelsien alongside equipment after a wipe.

Weaknesses:

Critical

• Kelsien Dependency: The deck falters if Kelsien is repeatedly removed or taxed, as most synergies require his presence.
• Artifact Reliance: Key equipment (e.g., Thornbite Staff, Basilisk Collar) are vulnerable to mass artifact removal like Vandalblast.

Moderate

• Board Wipes: Lacks mass recursion; rebuilding after a Damnation is slow without Sevinne's Reclamation.
• Graveyard Hate: Exiling graveyards disrupts Unearth and Call of the Death-Dweller.

Minor

• Limited Stack Interaction: Minimal counterspells or ways to protect against noncreature combos.
• Mana Base Speed: Multiple tapped lands (e.g., Savai Triome, Nomad Outpost) can delay early plays.

Most Important Cards:

• Basilisk Collar (Enables Kelsien’s one-sided board control)
• Thornbite Staff (Untap engine for infinite pings with deathtouch)
• Revel in Riches (Alt win condition via treasure hoarding)
• Mari, the Killing Quill (Card draw and treasure generation)
• Lightning Greaves (Essential protection for Kelsien)
• Stoneforge Mystic (Tutors critical equipment)
• Vorpal Sword (Game-ending combat trigger)
• Swiftfoot Boots (Hexproof for Kelsien)
• Boros Charm (Protection or finisher)
• Otharri, Suns' Glory (Token generation and recursion)

Attribute Ratings:

Speed: 5/10

• Can threaten wins via combat or combo by Turns 8-10, but setup requires multiple pieces and board control.

Resilience: 6/10

• Protection spells and recursion (e.g., Malakir Rebirth, Unfinished Business) mitigate removal, but Kelsien’s high commander tax is punishing.

Consistency: 7/10

• 10+ tutors and card draw engines ensure access to key equipment and synergies.

Interaction: 6/10

• Efficient spot removal (Anguished Unmaking, Fracture) and Kelsien’s pinging handle creatures, but lacks counterspells for noncreature threats.

Rating Justification:

This deck operates as a tuned casual build with focused synergies and multiple win paths, but its reliance on Kelsien and moderate speed cap its ceiling. It can consistently control the board and threaten wins via combat or treasure/voltron combos around Turns 8-10, aligning with optimized casual tiers.

Power level: 5.0 - 5.5