Whirlwind is an Attack card for the Ironclad. It deals 5 damage to every enemy one time for every bit of Energy spent. As an Uncommon card, it appears as a reward for combat, although less often than Commons.
Upon upgrade, each hit deals 3 more damage.
As a multi-hit attack, it benefits highly from Icon Strength.png Strength so long as more than 1 Energy is used.
Although using it with 0 Energy will have no immediate effect, it still counts as an Attack card played.
If duplicated with Duplication Potion Static.png Duplication Potion, Double Tap, Echo Form, or Necronomicon.png Necronomicon (If X is 2 or greater), the value of X will be preserved for the copied card.
ChemicalX.png Chemical X allows for Whirlwind to deal damage 2 more times, even if no Energy is used to play it.
When unupgraded against single enemies, it is better to use Strikes than burn all your energy on 5 damage instead of 6. This can make Whirlwind a card you might want to upgrade sooner.
Weekly Patch 46: Adrenaline
Adding VFX for Whirlwind card.
Weekly Patch 42: Reboot
Adding SFX for Whirlwind card + Guardian enemy.
Updating SFX for Whirlwind (card AND Guardian enemy).
Weekly Patch 40: Forethought
Whirlwind card gets an additional SFX.
Weekly Patch 27: Hello World
Fixed issue where playing cost X cards quickly after energy gain cards failed. Offering -> Whirlwind
Weekly Patch 10: Quality of Life
Removing 'Spend all [R].' from all X-cost cards for consistency.
Fixed bug where cost X cards do not work with energy gain cards if played too fast.