Short answers, pulled from the story.
Adam Driver's casting as an unnamed role that became Kylo Ren was first announced on the 29th of April 2014. The name and design were officially revealed later in a Lucasfilm-designed Topps-style trading card mock-up published by Entertainment Weekly on the 11th of December 2014.
Ben Solo trained as a Jedi alongside fellow students named Voe, Hennix, and Tai under Luke Skywalker. These three companions accompanied him on missions to Elphrona where they encountered the Knights of Ren and witnessed the destruction of the Jedi Temple.
Kylo Ren and Rey are revealed to be a dyad in the Force described as soulmates in the Force or twins of destiny. Their connection allows them to communicate telepathically across distances and share life energy during their final confrontation with Palpatine.
Adam Driver won the 2016 Saturn Award for Best Supporting Actor for his portrayal of Kylo Ren in The Force Awakens. This victory made him the first Star Wars actor since Alec Guinness to receive this specific honor from the Academy of Science Fiction, Fantasy and Horror Films.
Ben Solo sacrifices his own life by transferring his life essence into Rey to revive her after she collapses following the defeat of Palpatine. He dies in Rey's arms while his body fades away into the Force alongside Leia Organa.