Darkness

Darkness is an affect that only a few attacks in the Super Smash Bros. series can cause and even fewer characters can utilize it. It takes the appearance of dark purple flames and generally only evil characters can use it. Darkness wasn't introduced until Super Smash Bros. Melee, where only two playable characters and two bosses could use it.(See ahead.) In Super Smash Bros. Brawl, 3 playable characters could activate Darkness along with one boss.(See ahead.) Here is a list of characters that can use Darkness in the Super Smash Bros. series and the attacks that cause them.

Bosses
Crazy Hand-Spider Crawl, Flying Punch Catch (Master Hand Combo Move),Triple Poke (First Hit),Bombs (SSBM only)

Giga Bowser-See ahead

Playable Characters
Ganondorf-Forward Smash,Warlock Punch,Flame Choke (Brawl only),Gerudo Dragon (SSBMonly), Dark Dive (Ending Uppercut, SSBB only),Wizards Foot, Beast Ganon (Dash)

Mewtwo (SSBMonly)- Shadow Ball (After tossed), Forward Throw (Shadow Balls), Forward Air, Forward Smash, Down Smash, Up Smash, Dash Attack, Neutral Attack.

Giga Bowser-Forward tilt, Up tilt, Down Tilt, Forward Air

Olimar-Pummel, Pikmin Throw, Pikmin Chain (White Pikmin)

Kirby-Can Copy Warlock Punch, Shadow Ball, or Pikmin Throw.

Trivia

 * While Olimar's White Pikmin injects poison, it is technically uses darkness.
 * More of Crazy Hands attacks involve Drakness, signalling he may be more inclined to evil than Master Hand.