I think so.
I found them at Port Royal.
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.
Kingdom Hearts is the collection of hearts that the Organization XIII has, they are the hearts that Sora took from the heartless, the hearts rose up from the dead heartless and went to Kingdom Hearts, which is in The World That Never Was.
They're found in Beast's Castle, Olympus Coliseum and Timeless River.
Nope.
Port Royal(Level 20) Ceberus Cup Olympus Collesium and the other cups
The Trickmaster is a boss villain in the Kingdom Hearts games, found in the Wonderland. He is a Heartless.
I think to keep the trapped hearts inside
You have to find lots and lots of heartless.
They are heartless. Tough, tremendously strong heartless. Watch Out!! :D
Kingdom Hearts 2 is the sequel of Kingdom Hearts, in Kingdom Hearts 1, it was just about Heartless and killing Ansem for the final fight to end the Heartless' attacks for hearts. In Kingdom Hearts 2, it has Heartlesses and Nobodies, the empty shells of the bodies that the Heartless have the taken the heart from. The final fight in Kingdom Hearts 2 is Xemnas, ironically, the Nobody of Ansem, which is a Heartless. In Kingdom Hearts 2, Sora gets taller, so he gets new clothes, new Keyblades, new abilities and all sorts. But the overall way of playing and story is the same. Go to worlds of all sorts from Disney to kill Heartless and Nobodies to eventually meet Organisation XIII, the leader of the Nobodies and fight Xemnas, the leader.
You battle them