Ogre

The Orcus (オーガ) is a Pureblood Heartless that appears in Kingdom Hearts 358/2 Days.

Kingdom Hearts 358/2 Days
''Though faster and more powerful, these Heartless are otherwise the same as the Invisible. They attack with a fearsome shockwave.'' ''Time your combo finisher so it connects right after they catch their sword. This will cancel the shockwave and leave them open.''

Kingdom Hearts 358/2 Days

 * Halloween Town
 * Twilight Town

Kingdom Hearts 258/2 Days
The first time Roxas and Xion encounter an Orcus is on Day 352 in Halloween Town. It was revealed that the Orcus was actually Xion to Roxas and Roxas to Xion. This was a trap devised by the more superior Organization members to test who is the stronger member.

Strategy
The Orcus has four main attacks. If you know the signs you can see them coming. The easiest way to defeat him (but not the best) is to strike right after he either flies toward you slowly and then strikes and to hit him after he fires out the purple balls. The hardest attack to dodge is when he sends his sword flying around the area, homed onto you. Then after the sword passes you a few times the Orcus will appear (you know when there is a big purple ring in the sky) and create a shockwave. The best way to try and dodge his flying sword is to roll out of the way. If you time it just right it should work. But if you do get hit make sure to heal yourself quickly. Another way to attack him is to perform an aerial combo against him when he comes out to use a shockwave attack. Just jump up and perform a combo. If you time it right the Orcus will be stunned and you'll be free to attack him without any counters or dodges, but make sure you get out of there quickly when he recovers!! Another note, don't use Thunder spells against him because they heal him.