So, in the second movie Dark Heart repents of his evil and becomes a real boy. Good for him. However, he has no parents, no birth certificate or any other kind of records, and no experience whatsoever with the world outside his pocket dimension. So, he's basically a homeless orphan, with nowhere to go.
But that's not so bad; the Bears took care of a case like that in the first movie.
Kind of moot considering the kids seem to be living their lives in a summer camp with no adults. Maybe they're all orphans.
The snark aside, in a way consistent with the way the Care Bears universe works, he'd probably go home with his friend and be adopted by her parents.
What is Dark Heart in the first place and why does such a seemingly powerful entity care so much about the Care Bears and this one stupid summer camp??
He's Evil. He's just an elemental force of hatred that exists to make the world a worse place. Consider him the flip side of the coin to whatever sort of energy gives the Care Bears their powers of love and kindness.
Also in the 2nd movie: where do the Care Bears come from? They are shown sailing a boat in the middle of the sea and then being taken to Care-a-Lot by some giant Star-God. Are they from Earth? Another Planet? Another Dimension? Why are all of them babies? Did Dark Heart kill all the adults but two?
In the UK comics they were normal animals given their new forms by the Great Star, but its not officially a canon-set-point.
I assume they were from another dimension.
1) They're from the same place faeries, dragons, and other mythical or spiritual creatures are from. Whether you consider that to be hidden parts of Earth or some other realm sort of depends on your own interpretation. 2) Yes, Dark Heart probably did kill everyone else, they just didn't say straight-out "Dark Heart killed our entire race and this ship full of children is our last desperate hope against extinction" because it's a film intended for slightly-above-toddler-age children.
In the DIC TV series and the first two films, Billie Mae Richards voiced Tenderheart Bear and Jim Henshaw voiced Bright Heart Raccoon. However, in the Nelvana TV series, their roles switched. What reason was there for that? (Correction: According to The Other Wiki, it was Walker Boone who voiced Bright Heart in the DIC series. Jim Henshaw voiced Bright Heart in the first two films. Thank you.)
Maybe they were jealous of each other?
Doubtful. There has to be some type of reason.
Maybe they just couldn't remember who played whom. It's not like the Care Bears got very unique characters, after all.
It's possible doing the character voice was more tiring for their vocal chords, and they realized that the opposite voice was a lot easier for them to do. Unless they used the same voice for different characters, in which case the person above is probably right and they just didn't care.