ホイッスル

• Type: Attack
• Cost: 3
• Rarity: Ancient (Colorless)
• Effect: Deal 33 damage. Stun the enemy. Exhaust.

Upgraded

• Cost: 3
• Effect: Deal 44 damage. Stun the enemy. Exhaust.

A top-tier single-target removal attack: 33 damage plus Stun on one card. A-tier. The Stun completely cancels the target's next action, so you can nullify lethal elite or boss attacks while dealing heavy damage. Upgraded pushes damage to 44, enough to halve a mid-act elite's HP with a single card. It Exhausts, so it is once per combat, but that one use can flip a fight. The big downside is cost 3: without Energy support, playing much else the same turn is hard.

The best timing is a turn the enemy is telegraphing a big attack or a buff move. Stunning skips their action while your 33 damage still lands, giving offense-defense in one card. Cost 3 limits your other plays, so pair it with Brightest Flame or Enlightenment for Energy help, or commit fully on turn 1. Under Echo Form, Whistle triggers twice for 66 damage plus Stun, sinking most elites in one turn. Since it Exhausts, save it for the decisive moment.

• Echo Form: double trigger deals 66 damage plus Stun. Strong even in boss fights.
• Enlightenment: drops Whistle to cost 1, freeing room for other plays the same turn.
• Brightest Flame: 2 Energy and 2 draw cushion the cost-3 burden so Whistle plus extra cards fits.
• Vulnerable sources: a Vulnerable enemy takes 33 x 1.5 = 49 damage from Whistle; upgraded hits 66.
• Necronomicon (Relic): cost-2-or-more attacks auto-trigger twice. Whistle becomes 66 damage plus Stun.
• Feeding Frenzy: temporary +5 Strength turns Whistle into 38 damage (49 upgraded).