Flex

Flex is a 0-cost Ironclad skill that grants 2 temporary Strength (4 upgraded), which expires at the end of your turn. Because Strength is lost at end of turn, Flex only benefits attacks played in the same turn it's used. The key is burst: playing Flex and then a multi-hit or Strength-amplified attack immediately maximizes its value. With Heavy Blade's 3x Strength multiplier, 2 temporary Strength from Flex adds 6 bonus damage for free.

Flex is best in decks that can capitalize on burst Strength windows — play Flex, then play all your damage cards in the same turn. It's weaker in decks that spread attacks across multiple turns. Upgraded Flex at 4 Strength is noticeably stronger, particularly with multi-hit attacks where each hit gains the full bonus. A strong zero-cost pickup in offensive builds.