ネクロバインダー

• Type: Skill
• Cost: 1
• Effect: Gain 6 Block. If you applied Decay this turn, gain Block 2 additional times.

Upgraded

• Cost: 1
• Effect: Gain 7 Block. If you applied Decay this turn, gain Block 2 additional times.

An S-class defensive card for Decay decks. If Decay was applied this turn, the skill fires Block twice more, landing 3 total rounds of Block (6×3=18, upgraded 7×3=21) for just 1 cost.

Combined with Decay-applying cards — Negative Wave (AoE 7-11 Decay), Nowhere to Run, Retribution, Countdown — you lock in 18-21 Block every turn and build a fortress. Practically mandatory for any Decay deck.

Rating: S-tier (top defense of Decay decks, absurd cost efficiency)

• Fire a Decay-applier like Negative Wave or Retribution first, then play Door to Death for 18-21 Block that turn
• With Cloak of Shadow (Block 2-3 per Decay applied), the Decay phase itself adds Block while satisfying Door to Death's condition
• Countdown (turn-start automatic Decay 6) automatically fulfills Door to Death's condition every turn
• Upgraded 7 Block per trigger = 21 total Block, even stronger

• Negative Wave: AoE Decay 7-11 + 5-6 Block. Follow up with Door to Death for 23-27 total
• Countdown: turn-start auto-Decay 6. Door to Death's condition is fulfilled every turn on autopilot
• Cloak of Shadow: +2-3 Block per Decay applied. Stack Block during the Decay phase before Door to Death
• Retribution: Decay 13 + 1 draw. Chain Retribution to trigger Door to Death
• Oblivion: Decay 3 per card played this turn. Instantly satisfies Door to Death's condition

• Act 1 early: high priority — first defensive pick for Decay deck hopefuls
• Act 1 late: top priority — even one Decay-applier makes this a 1-cost 18 Block
• Act 2+: top priority — essential defensive foundation for Decay decks; running 2 copies is worth considering
• Boss reward: top priority — in drawn-out boss fights, stable 18-21 Block per turn guarantees survival