The Rift was the name of the portal that pulled in the Light and Dark dragons and also the name of the dimension they ended up in. In the Rift time stood still, and dragons didn't die, age or were born, so the dragons coming out were exactly the same as those living during The Dark War. However one Dark Dragon did not survive The Cataclysm, the evil Void, who was killed because of dimensional distortions. The Rift re-opened twice by the help of the wizards to bring the lost magics back to our world, and after then the portal and dimension have never been seen again.