Sword Kirby wears a long green hat like Link's hat.
Kirby's Adventure and Kirby: Nightmare in Dream Land
Kirby usually attacks just by slashing the sword horizontally.
Kirby Super Star and Ultra
Kirby can use much more attacks then just slashing the the sword. Meta Knight lets Kirby use a sword to fight him.
Kirby & the Amazing Mirror and Kirby: Squeak Squad
Sword Kirby can use his sword underwater and most commonly used by the other Kirbys.
Kirby's Return to Dream Land
It has a super form called Ultra Sword.
Super Smash Bros. series
It is commonly a trophy in the series
Super Smash Bros. for Wii U trophy description
- That green cap sure does make Kirby look heroic, doesn't it? Maybe wearing it just inspires Kirby, but while he's wearing it, he gets all kinds of neat moves, like Spin Slash, Multisword Attack, and Sword Dive. He's even able to pull off these moves in the air, on the ground, or underwater!
- Nintendo Entertainment System - Kirby's Adventure - 05/1993
- Nintendo 3DS - Kirby: Triple Deluxe - 05/2014