FIRE
4
2Crystal Keeper
Archetype:
Crystal Beast
ATK:
1500
DEF:
1800
View:
4464
[ Pendulum Effect ] Each turn, the first time an "Ultimate Crystal" monster(s) and/or "Crystal Beast" card(s) you control would be destroyed by card effect that turn, it is not destroyed. [ Monster Effect ] If a "Crystal Beast" monster you control battles an opponent's monster, during damage calculation (Quick Effect): You can Tribute this card from your hand or face-up field; your battling monster's ATK/DEF become double its original ATK/DEF during that damage calculation only, but it is destroyed at the end of this Damage Step.
Crystal Keeper — Power Evaluation
Final Score: 49 ± 6 · Confidence: Medium
- Intrinsic: 47 · Deck: 51 · Meta: provisional
- Primary role: Utility · Secondary: Board breaker, Removal
Why it scores here
Crystal Keeper is a Crystal Beast support card, not a power card. Its Pendulum effect protects Crystal Beast and Ultimate Crystal monsters from card-effect destruction once per turn, which is soft interaction. Its monster effect is a hand-or-field Tribute that doubles one battling Crystal Beast's ATK/DEF for a single damage step, which converts a battle but costs the card and does not build a board. The card's 1500 ATK and Level 4 body earn nothing on their own. Its score comes from being a near-universal Crystal Beast staple (78 of 78 sampled decks) rather than from any demonstrated combo role, which the rubric treats as consistency, not strength.
Axis scores
| Axis | Score | Evidence |
|---|---|---|
| Accessibility | 60 | Present in all 78 sampled decks and live in hand or the Pendulum zone, but no searcher or combo-start evidence exists for it (observed deck frequency, inferred live access). |
| Combo & Conversion | 30 | Pump effect converts one battle into a win but builds no extra board, and combos_evidence records zero boards (verified from card text, no combo data). |
| Resource Economy | 25 | Tribute from hand is a card cost and the boosted monster is destroyed at end of damage step, so the card is net negative with no refuel (verified from card text). |
| Effect & Interaction | 45 | Once-per-turn protection from card-effect destruction for Crystal Beast and Ultimate Crystal monsters is soft interaction limited to one archetype (verified from card text). |
| Material Utility | 35 | Level 4 Warrior FIRE body with no clean material routing shown in evidence; material use is inferred, not measured (inferred). |
| Resilience & Flexibility | 60 | Works from hand or field and in the Pendulum zone, with a once-per-turn protection that can recur on later turns (verified from card text, inferred redundancy). |
| Deck-Building Efficiency | 65 | Typically runs 1 copy (avg 1.29 per deck), uses a Pendulum slot with no garnet or lock restriction (observed from deck copies, verified from card text). |
Calculation
Weight profile: Primary role Utility (default profile); no secondary blend applied. Intrinsic ≈ 47, Deck ≈ 51, Meta = provisional. Modifiers: none. Final formula: 0.40*Intrinsic + 0.60*Deck
Strengths
- Near-universal Crystal Beast inclusion (78 of 78 sampled decks, 47 in the core archetype)
- Protects Crystal Beast monsters from card-effect destruction once per turn
- Quick-effect battle pump usable from hand or field
Weaknesses
- Card-negative once used: Tribute cost and destruction at end of damage step
- Effect works only for Crystal Beast battlers
- No combo or searcher evidence; combo role is text-only inference
Counters / choke points
- Effects that negate the protection or the Tribute activation
- Removal that bypasses card-effect protection, such as battle destruction or non-effect removal
Best use
Pendulum protection and battle-step pump in a Crystal Beast shell. Decks: Crystal Beast (archetype 610). Suggested copies: 1.
Evidence & gaps
- Verified: Pendulum effect protects Crystal Beast and Ultimate Crystal monsters from card-effect destruction once per turn (card text); Monster effect is a Quick Effect Tribute from hand or field that doubles a battling Crystal Beast ATK/DEF during damage calculation, destroyed at end of damage step (card text); Present in 78 of 78 sampled decks, 1 copy average (deck evidence)
- Observed: Partners Crystal Beast Rainbow Dragon, Crystal Bond and Rainbow Bridge co-occur in 97.4% of decks (deck evidence); Guides place Crystal Beasts as a search and float engine rather than beaters (guide snippet)
- Inferred: Pump effect is a battle-step conversion tool rather than a board builder (inferred from text, no combo data); Level 4 body has limited material routing (inferred, not tabled)
- Data gaps: no combos supplied, so combo conversion is text-only inference no banlist token, assumed 3 copies (unlimited) no usage statistics (StatisticsCard), so archetype inclusion is inferred from the deck sample only no rulings supplied for the once-per-turn and damage-step timing