From Kirbypedia

Name:	Light
First Game:	Kirby's Adventure
Enemies Copied from:	Cool Spook
Helper:	None
Anime Episode(s)	None

A unique ability in several respects, Light carries several rare titles with it. The ability first appeared in Kirby's Adventure, then later only in the remake, Nightmare in Dream Land. Aside from its rare appearance in the game series, the ability rarely appears within games, too, and is only obtainable in a handful of stages. To further set off this power from others, it is one of the few limited use abilities, like Crash and Mike, having only a single discharge.

This power was also the first ability to be non-offensive and purely utilitarian. No damage is caused in using Light. While the Light ability only appears in two games, its function has been reused. Spark, typically when used in conjunction with the pet Kine, can illuminate a room in much the same way.

Games

Kirby's Adventure

Light can only be used once and cannot injury any enemies. The only function it has is to light up a darkened room to reveal hidden doors in the shadows. When used, Kirby throws a dazzling ball of light upward that flashes and brightens the surroundings.

Kirby: Nightmare in Dream Land

There is no difference between Light in the remake and its predecessor. The power still lights up rooms. However, rather than the peach tinting to denote the presence of this power, the pink shade is kept but he occasionally flashes brighter.

Kirby Copy Abilities:

Cupid - Animal - Backdrop - Ball - Balloon - Baton Twirling - Beam - Bomb - Bubble - Burning - Clean - Cook - Copy - Crash - Cutter - Fighter - Fire - Freeze - Galaxia - Ghost - Hammer - Hi-Jump - Ice - Iron - Jet - Laser - Light - Magic - Metal - Mike - Minimum - Missile - Mirror - Needle - Ninja - Paint - Parasol - Plasma - Sleep - Smash - Smash Bros. Abilities - Spark - Stone - Suplex - Sword - Throw - Top - Tornado - UFO - Water - Wheel - Wing - Yo-yo

Final Weapons:

Star Rod - Love-Love Stick - Rainbow Sword - Star Chariot - Master - Triple Star - Block