Regulus Arcturus Black

Biography
Regulus was the favorite child of his parents, as he supported all the values that his family supported as well. He also became a follower of Lord Voldemort at about the age of sixteen.

After Voldemort left the Black family house elf to die while creating a horcrux, Regulus became less loyal to Lord Voldemort.

Regulus then went to the secret island where Voldemort's horcrux was hidden. He drank the poison and made his house-elf take the horcrux and destroy it. When the Inferi emerged from the lake, Regulus was killed and his house-elf took the horcrux and replaced it with a fake one.