ネクロバインダー

• Type: Attack
• Cost: 1
• Effect: Deal 10 damage. Upgrade 2 random cards in your discard pile.

Upgraded

• Cost: 1
• Effect: Deal 12 damage. Upgrade 3 random cards in your discard pile.

A unique card that deals damage AND upgrades the deck in one play. 1-cost 10-12 damage and 2-3 random discard-pile upgrades.

Because the upgrades hit your discard pile, the longer you use Power Drain the more the whole deck snowballs upward. Randomness means you can't pick targets, but most cards gain meaningful value when upgraded so it rarely whiffs. Especially valuable when the deck is large or when several cards still need upgrading.

Rating: B-tier (deck-improving Attack with long-term compounding)

• Spam it early to get passive upgrades on whatever lands in the discard
• Smaller decks make target cards more likely — best used after deck thinning
• Upgraded version hits 3 cards per cast — a few turns is enough to upgrade most key cards
• Combine with Gather (add 3 hand cards to draw pile) to duplicate upgraded copies

• Forbidden Grimoire: post-combat deck thinning helps control which cards sit in the discard pool
• Gather: puts 3 hand cards back into draw. Duplicates upgraded cards fished out by Power Drain
• Nowhere to Run: upgrade bumps base Decay to 15, a very valuable random-upgrade target
• Deathbringer: upgrade raises Decay 21 → 26, one of the biggest beneficiaries of Power Drain's RNG