Shadow Stalker and Dark Thorn

The Shadow Stalker is a boss from Kingdom Hearts II.

Bearing a close resemblance to Darkball Heartless, an enemy from Kingdom Hearts the Shadow Stalker is the third boss of Beast's Castle. Called upon by Xaldin to capture Belle as a last effort to turn Beast into a Heartless, the chandelier-like creature attacks Sora and his friends by possessing the windows, pillars, chandelier and floor of the castle ballroom. Upon being defeated, it transforms into the Dark Thorn. When merged with the floor, it attempts to devour its foes. Sora can avoid this by staying in motion and jumping. When merged with the window, the Shadow Stalker creates a surge of dark power along the floor, which leaves safe spots to stand on. When merged with a pillar, it attacks with a fierce slash attack. To defeat it, deplete the possessed object's HP Gauge and use the reaction command to force the Shadow Stalker out of the object. The Shadow Stalker is believed by some to be a representation of Beast's soul held captive by his curse.

Kingdom Hearts II
A Heartless that attacked Belle in Beast's Castle.

It jumped around on the floor, pillars, and chandelier of the ballroom, creating mayhem.

Kingdom Hearts II
The Shadow Stalker appears only in Kingdom Hearts II to date. It is the penultimate boss of Beast's Castle during the first visit to the world, summoned by Xaldin to capture Beast's heart.

Strategy
The Shadow Stalker will possess the various parts of the ballroom during the encounter to attack the party;
 * Windows: The Shadow Stalker flies into the windows, and causes a giant flash to pass over the floor. Retreat behind the pillars to avoid this.
 * Floor: When the Shadow Stalker disappears into the floor, it will attack Sora from beneath him. Jump sideways when the floor underneath him glows to avoid the attack.
 * Chandelier: The enemy Heartless will fly up in the air, and bring the chandelier crashing down to the ground, triggering a shockwave. he chandelier will turn, firing energy beams. Attack the chandelier to release the Shadow Stalker. It has 59 HP.
 * Pillar: The Shadow Stalker will fly into the pillars, which it will cause to flail and thrash about. Attack them to release the Shadow Stalker. It has 39 HP.

Once you have depleted the HP of the chandelier or pillars, the Release reaction command will appear. The Shadow Stalker will fly out of the object it was possessing, releasing Drive and MP Orbs. Take this opportunity to bombard the enemy with attacks, or unleash a Limit if you feel you can survive MP Charge, or have an Ether handy. This process will continue until victory is obtained.