Simplify the following text for a Grade 7 native English-speaking person.
Original: In 2003 , he appeared in the music video for singer Dido 's hit single `` White Flag '' , and was the voice of Leon ( Squall Leonhart ) in the video game Kingdom Hearts , but he did not reprise his role in the sequel .
Simplified: In 2003 , he appeared in the music video for singer Dido 's `` White Flag '' . He was also the voice of Leon ( aka Squall Leonhart ) in the video game Kingdom Hearts .