It is in hollow bastion when darkness surrounds the world.
After you have completed the 1000 heartless fight,you can retrace your steps later on and one area before the 1000 heartless fight area you will end up in the crystal fissure with about 4 treasure chests and a save point.
In Kingdom Hearts 2, the Battle of 1000 Heartless occurs when Sora has to fight 1000 Heartless alone in Hollow Bastion. It's easy enough; just keep using action commands and you should be done easily.
After the 1000 heartless fight? I know that when yuou get past the broken Bailey, there is that place where you fought Demyx, go through that and it takes you to a path, which if you follow, you should get to Crystal Fissure.
In Hollow Bastion, Sora fights 1000 Heartless alone (a gauge tells how many he's defeated during the fight), because he gets separated from Donald and Goofy. After killing all 1000, a cutscene plays.
If I recall correctly, sora continues on, individually, to fight 1000 heartless.
nothing special happens, you have to defeat 1000 heartless in one of the missions in hollow bastion
It's just before 1000 heartless fight. and after Demyx fight. When Goofy gets hit on the head u go automatically here
Story-wise: To effectively defeat more Heartless. Game-wise: To challenge Sora to defeat all 1000 Heartless by himself.
After the 1000 Heartless Battle, go to the place after the area where you fought them. Press the reaction command "Approach" on Sephiroth. But beware, you must be at least Level 80 to fight Sephiroth.
I'm not sure whether or not this is true, but due to the fact that Sora, Donald, and Goofy split up right before Sora fights the 1000 Heartless, Donald and Goofy probably fought 1000 each as well.
fight heartless in the tornaments in Olympic Coloseium or in just run around the worlds and fight them.
In the battle of 1000 Heartless, the Nobodies easily defeated the Heartless, so Xemnas should probably be stronger then Fake Ansem.