These are ALL the combinations Kirby can do:

Fire+fire= firebird
Fire+ice= melting ice
Fire+spark= head fire
Fire+cutter= flame sword
Fire+spike= fire bow
Fire+bomb= fireworks
Fire+rock= hot rock blast

Ice+ice= snowball roll
Ice+fire= melting ice
Ice+spark=refridgerator
Ice+cutter= ice skates
Ice+spike= pointy ice tree
Ice+bomb= bomb snowman
Ice+rock= sliding ice rock

Spark+spark= giant electric
Spark+fire= head fire
Spark+ice= refridgerator
Spark+cutter= electric stick
Spark+spike= electric rod
Spark+bomb= light bulb
Spark+rock= electric controled rock

Cutter+cutter= giant boomerang
Cutter+fire= flame sword
Cutter+ice= ice skates
Cutter+spark= electric stick
Cutter+spike= giant pointy toothbrushes
Cutter+bomb= tiny throwing bombs
Cutter+rock= animal rock form

Spike+spike= pointy objects
Spike+fire= fire bow
Spike+ice= pointy ice tree
Spike+cutter= giant pointy toothbrushes
Spike+bomb= spike ball
Spike+rock= driller

Bomb+bomb= rocket launcher
Bomb+fire= fireworks
Bomb+ice= bomb snowman
Bomb+spark= lightbulb
Bomb+cutter= tiny throwing bombs
Bomb+spike=spikeball
Bomb+rock= dynamite

Rock+rock= giant rock
Rock+fire= hot rock blast
Rock+ice= sliding ice rock
Rock+spark= electric controled rock
Rock+cutter= animal rock form
Rock+spike= driller
Rock+bomb= dynamite