Umi

Umi — Power Evaluation

Final Score: 50 ± 7 · Confidence: Medium

• Intrinsic: 49.7 · Deck: 53.1 · Meta: provisional
• Primary role: Utility · Secondary: Combo enabler, Floodgate/Control

Why it scores here

Umi's printed text is only a 200 ATK/DEF swing, so its real value is the 'Umi' name: 54 recorded decks, 100% inclusion in Umi Control at a typical 1 copy, and a 61.1% co-deck rate with Ocean Dragon Lord - Kairyu-Shin show it is the Field Spell the archetype's payoffs are built around. Terraforming (40.7%) and A Legendary Ocean (38.9%) give it practical redundancy, which is why accessibility and deckbuilding efficiency are its highest axes. With zero recorded combo appearances and no card advantage, negation or removal in its own text, combo conversion and effect interaction stay low. The high ATK/DEF numbers on the monsters it touches earn it nothing here — this score is driven entirely by how reliably it turns a single slot into the archetype's engine.

Axis scores

Calculation

Weight profile: 0.7 Utility (default) + 0.3 Combo enabler. Intrinsic ≈ 49.7, Deck ≈ 53.1, Meta = provisional. Modifiers: Narrow payoff dependency (-2). Final formula: 0.40*Intrinsic + 0.60*Deck

Strengths

• Provides the 'Umi' Field Spell name that the archetype's payoffs are built around, appearing in 54 recorded decks (all main deck)
• 100% inclusion in Umi Control at a typical 1 copy, confirming a real, consistent role
• Practical redundancy: Terraforming co-decks 40.7% and A Legendary Ocean 38.9%
• Low slot cost — 32 of 54 decks run exactly one copy (avg 1.69)
• Legal in TCG, OCG, Master Duel and Duel Links, so it is available across formats
• Persistent Field Spell that keeps applying its ATK/DEF modifier every turn it remains on board

Weaknesses

• Printed effect is only a 200 ATK/DEF gain for Fish/Sea Serpent/Thunder/Aqua and a 200 ATK/DEF loss for Machine/Pyro — negligible without the archetype payoffs
• No card advantage, search, draw or GY refuel; it never replaces itself
• Provides no disruption, negation or removal on its own
• A single Spell/Trap removal effect answers it and can collapse the Umi-dependent line
• 0 recorded combo appearances, so its board-building contribution is unmeasured
• Not a top card in any format ranking, indicating it is an enabler rather than a standalone power card

Counters / choke points

• Spell/Trap removal such as Cosmic Cyclone or Twin Twisters (inferred)
• Field Spell removal that clears the Field Zone (inferred)
• Hand traps that stop the searches used to find it (Ash Blossom & Joyous Spring appears alongside it in 55.6% of decks) (observed)

Best use

Field Spell enabler supplying the 'Umi' name for archetype payoffs. Decks: Umi / Ocean Dragon Lord - Kairyu-Shin control, Umi Control, Shark. Suggested copies: 1.

Evidence & gaps

• Verified: Card text: all Fish, Sea Serpent, Thunder and Aqua monsters on the field gain 200 ATK/DEF, and all Machine and Pyro monsters on the field lose 200 ATK/DEF (verified from description); Card is a Field Spell in the Umi archetype, legal in TCG, OCG, Master Duel and Duel Links (verified)
• Observed: 54 recorded decks run it, all in the main deck, at an average of 1.69 copies (max 3) (observed); Umi-archetype decks account for 42.6% of those decks; Shark 13%; Umi Control shows 100% inclusion with 1 typical copy (observed); Top partners include Ocean Dragon Lord - Kairyu-Shin 61.1%, Bahamut Shark 59.3%, Number 101: Silent Honor ARK 55.6%, Ash Blossom & Joyous Spring 55.6%, Number 4: Stealth Kragen 51.9% (observed); Terraforming co-decks 40.7% and A Legendary Ocean 38.9%, indicating search/redundancy is part of the package (observed); 0 combo appearances across the recorded sample (observed); Not flagged as a top card in any format ranking (observed)
• Inferred: It is played for the 'Umi' name that enables the archetype's payoffs rather than for its 200 ATK/DEF swing (inferred from deck composition plus text); A Legendary Ocean co-decking 38.9% suggests an additional route to an 'Umi'-named card, but the evidence pack does not state the interaction (inferred); Losing the Field Spell to Spell/Trap removal likely turns off the Umi-dependent control line (inferred); Multi-format legality plus Terraforming access makes it a low-cost 1-of enabler in its home decks (inferred)
• Data gaps: no combos supplied — combo conversion is text-only inference no banlist token — assumed 3 copies (unlimited) no explicit evidence on how A Legendary Ocean substitutes for the Umi name no dated metagame sample, so meta power is null only one guide mention with no substantive commentary on this card's role