Mermail Deck #770258 — Yu-Gi-Oh! OCG

40 Main, 15 Extra, incl. First Penguin x3, Mulcharmy Purulia x3, Siren Vortex of Atlantis x3. Created Oct 20, 2026 by YGO Mod.

Created by: YGO Mod (20517634)

Created On: 10/20/2026

Official AI Deck Power Analysis

MidrangeConfidence: MediumEvaluated Oct 20, 2026

30± 10/ 100

Power Score

Structural 58

Reliability 55

Going First 62

Going Second 60

Deck — Deck Power Evaluation

Final Contextual Deck Power: 30/100 (±10 · Confidence: Medium)

Overall score	Value
Structural Deck Power	58
Going First	62
Going Second	60
Meta Power	provisional
Tournament Reliability	55

Primary strategy: Midrange
Secondary strategies: Stun, Combo
Format: ocg

Legality

Main 40 / Extra 15 / Side 0 — status: Illegal. 1 violation(s).

Identity & game plan

Win condition: Atlantis/Umi board of WATER monsters (Neptabyss, Dragoons, Poseidra, Levia-Dragon) converting into Link and Xyz pressure, with Azure Ocean Dragon Lord - Neo-Daedalus Rage as the closer; Hand-trap and negation-backed disruption (Ash Blossom, Maxx C, Droll & Lock Bird, Dominus Impulse) that buys time for the Atlantis engine
Turn 1 (going first): T1 Fish Sonar, Advent of Atlantis or Neptabyss to search a second Atlantean/Atlantis piece, then Atlantis, City of the Sea Dragon or Umi to turn on the Level-reduction and Umi effects
Turn 2 (going second): Hold Ash Blossom, Maxx C, Droll & Lock Bird or Dominus Impulse against the opponent's first summon or search, then rebuild with Warchief or Siren Vortex searches
Recovery: Warchief and Neptabyss recursion from the GY, Atlantean Dragoons GY search, and Monster Arms of Atlantis GY revival of Atlantis-mentioning monsters
After siding: No Side Deck is registered, so there is no post-side plan; the list cannot adapt between games

Why it scores here

The list is Illegal because it runs two copies of Bahamut Shark, a Forbidden card, so the score is a theoretical, structural-only read and is capped at 30 rather than given a normal Final Contextual score. Structurally the deck reliably opens a searcher (P(at least one searcher in a 5-card opening hand) about 0.95 by the searcher-text group) and has a real Atlantis/Umi engine with a layered hand-trap and negation suite that rates well on end-board interaction (D7 70). Its weak points are the absence of a Side Deck (D12 25), no recorded combos to confirm a median or ceiling (D3 and D4 are inferred from text only), and an Extra Deck that spends two slots on a forbidden card. The deck is labelled Mermail, but none of its cards are Mermail; the score comes from its Atlantis/Umi/Atlantean/Daedalus system and its consistency, not from the archetype's popularity or from averaging card scores.

Dimension scores

#	Dimension	Score	Evidence
D1	Engine Accessibility & Consistency	68	P(>=1 searcher in 5-card hand) about 0.95; Atlantis engine starters (Siren Vortex x3, Warchief x3, Neptabyss x2) with 3-copy redundancy (Inferred)
D2	Opening-Hand Quality & Brick Management	60	Hypergeometric draw odds are reasonable for a 40-card main with 13 singletons, but Extra-Deck-dependent bricks and situational hand traps reduce functional hands (Inferred)
D3	Combo Conversion & Ceiling	55	No recorded boards; ceiling from card text only, via Atlantis/Umi chains, Link and Xyz summons, and Abysstrite/LeVirtue-style lines that are absent from the list (Inferred)
D4	Combo Floor & Median Output	45	No combo data; median output is unknown and is estimated low because the best payoffs are missing from the list (Inferred)
D5	Interruption Resilience & Route Redundancy	62	Six hand traps and two-copy searchers give multiple independent answers to one interruption (Inferred)
D6	Resource Economy, Recovery & Grind	60	GY recursion via Warchief, Neptabyss and Dragoons plus Monster Arms revival gives regeneration (Inferred)
D7	End-Board & Interaction Quality	70	Ten negation-text cards and five removal-text cards, including Virtue Stream, Monster Arms and Dominus Impulse (Verified card text, Inferred quality)
D8	Going-Second & Board-Breaking Power	60	Going-second disruption from Maxx C, Droll & Lock Bird and Dominus Impulse, with limited board-breaking beyond the engine (Inferred)
D9	Offensive Pressure & Closing Power	62	Closers include Azure Ocean Dragon Lord x2 (ATK 2900), Poseidra (ATK 2800) and Levia-Dragon (ATK 2600); Bahamut Shark cannot be counted (Verified stats, Inferred)
D10	Main Deck Efficiency & Flexibility	55	40 main cards with 24 distinct, a 17-searcher text load, and 55 of 40 main copies outside the exact Mermail name, which dilutes engine coherence (Verified composition)
D11	Extra Deck Efficiency & Coverage	50	Extra Deck of 15 includes 2 copies of Forbidden Bahamut Shark, so those slots are dead in a legal build; other Link and Xyz picks are on-plan (Verified)
D12	Side Deck Adaptability	25	No Side Deck is registered, so there is no post-side adaptability to score (Verified; scored low)
D13	Matchup Coverage & Format Fit	50	No tournament link and no dated metagame sample; Mermail archetype share is not applicable to this Atlantis build (Provisional)
D14	Pilotability & Error Tolerance	50	Multi-step Atlantis and Umi triggers with the Level-reduction and Umi interactions, plus many once-per-turn names, make it a mid-difficulty deck to pilot (Inferred)

How the score was computed

Strategy profile: Midrange. Structural ≈ 58, Going First ≈ 62, Going Second ≈ 60, Meta = provisional, Tournament Reliability ≈ 55. Modifiers: banlist_exposure (-8). Final formula: Uncapped: 0.80*Structural(57.7) + 0.20*TournamentReliability(55) + ContextModifiers(-8) = 49; capped to 30 because the deck is Illegal (theoretical/structural-only)

Probability & combo summary

Opening a starter: P(≥1) ≈ 0.95 · key two-card combo ≈ — · full-brick estimate ≈ — (all Inferred)
Combo output: best PowerIndex —, median —, board-per-starter —
Turn order: 0 going-first lines vs 0 going-second lines

Strengths

Strong searcher density (17 searcher-text cards) gives reliable early access to the engine
Layered interaction: 6 hand traps, 10 negation-text cards and 5 removal-text cards
Extra Deck link and Xyz closers (Azure Ocean Dragon Lord x2, Poseidra, Levia-Dragon) with real ATK

Weaknesses

Illegal as built: 2 copies of Forbidden Bahamut Shark
No Side Deck, so no post-side adaptation
Archetype label Mermail does not match the list; 55 of 40 main copies are outside the Mermail name

Critical choke points

Atlantis, City of the Sea Dragon x1 is the single field-spell enabler for the Umi/Level-reduction plan
The Extra Deck's two Forbidden Bahamut Shark slots are dead, so the closer count is effectively 13 Extra cards

Recommended changes

Priority	Remove	Add	Reason
1	2x Bahamut Shark (440556)	Two legal Extra Deck options already in the archetype's pool (for example a second Levia-Dragoon - Daedalus or an Atlantis-named Xyz)	Makes the list legal so it can receive a normal Final Contextual score; the Forbidden card is the only violation.
2	None (main deck is 40/40 legal size)	A 1-5 card Side Deck	A zero-card Side Deck gives no way to answer a known matchup and drops D12 to its floor.

Evidence & confidence

Verified: Legality: 2x Bahamut Shark vs 0 legal copies (Forbidden); all other copy counts are within limits; Main 40 / Extra 15 / Side 0 are within OCG size rules; Card text and stats for the listed cards
Inferred: Consistency estimates from hypergeometric draws (searcher 0.95, hand-trap 0.65); Engine and interaction quality from card text; Structural score and dimension scores
Provisional: Meta Power (no dated metagame sample); Matchup fit (D13), no tournament link
Data gaps: No combos supplied: combo floor, median and ceiling are text-only inference No tournament link: archetype meta-share and per-pilot match record are absent No win-rate telemetry exists in YGOVN Meta Power is Provisional unless a dated metagame sample is supplied No Side Deck registered Deck title is null and the Mermail archetype label does not match the card list

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More OCG Info

Mermail Breakdown