Sora's Heartless is a boss in Kingdom Hearts coded.
Strategy
Kingdom Hearts coded
Phase 1
Sora's Heartless looks like Dark Side and fights very similarly, except that every move unleashes a Debug Attack. The left fist is Blizzard, the right fist is Fire, the head launches Slow. That last one is the most annoying of the bunch. Avoid it at all costs. Focus on dodging attacks and then attack the fists when they are on the ground. You also have to make sure not to fall off the platform while dodging. It's quite a harrowing battle, but you can make it if you persevere.
Phase 2
Shadow-Sora is invincible under his shield. Notice that a white ghostly keyblade is hovering over the field. This is what you have to hit. If you can't find it, hold still a moment until it comes lunging at you. The target keyblade is different from the ones Shadow-Sora attacks you with, but looks similar. When you successfully attack it, Shadow-Sora will turn into a simple Shadow. Pummel this Shadow with a combo!
Phase 3
Dodge their attacks and wait for ghost-keyblades to appear. Hit the fake Shadow-Soras while their shields are down to make them disappear. If you miss your chance, hit their keyblades until they are open again. Repeat the keyblade-smacking pattern against the last remaining Shadow-Sora.
Phase 4
You'll fins yourself facing off against four Shadow-Soras, all with shields up. Now, whenever you defeat a Shadow-Sora, it will turn into a ghostly keyblade and keep attacking you, eventually turning back into its original form. Focus your attacks on the real one. Only bother with the fakes if they get in your way. At long last, he'll turn into a Shadow for good.
Phase 5
This is just a regular Shadow. Smash it. You win.