King Dedede hits in front of him with his hammer about 47 units. The first opponent hit will be flung into a caged ring and hit with a barrage of missiles, before Dedede uses his mask to become Masked Dedede and revs up his hammer and spins towards them, launching them with one final hit, dealing 71.5 damage in total. Anyone else in the vicinity of the initial swing will not be caught, but will still take 8% base damage from the hit.
During the Final Smash, King Dedede dons his mask to become Masked Dedede, his upgraded form from Kirby Super Star Ultra. The caged ring is reminiscent of the arena in which Kirby fights Masked Dedede, and Dedede's Super Dedede Hammer is used to fire missiles and perform Hammer Swing, both attacks used during his boss fight. In particular, the missile attack seems to resemble one of his attacks from Kirby's Block Ball.