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 was 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 attacked Sora and his friends by possessing the windows, pillars, chandelier and floor of the castle ballroom. Upon being defeated, it transformed into the Dark Thorn. When merged with the floor, it will attempt to devour its foes. Sora can avoid this by staying in motion and jumping. When merged with the window, The Stalker will create a surge of dark power along the floor, which leaves safe spots to stand. When merged with a pillar, it will attack 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
