Here's a list of characters and who they look like. The age of the celebrity does not apply to the character.

Lyric: Eriko Nakao

Christopher: Gerard Way

River: Sarah Hyland

Everest: Halsey

Randall: Harry Styles

Kayden: (Young) Kanye West

Sabbith: Kellin Quinn

Scott: Pete Wentz

Azaria: Tkay Maizda 

Bob: Ashton Irwin