Elliot Page Vanya Actor Tom Hopper Luther Actor David Castañeda Diego Actor Robert Sheehan Klaus Actor Aidan Gallagher Number Five Actor Emmy Raver-Lampman Allison Actor Justin H. Min Ben Hargreeves Actor Colm Feore Sir Reginald Hargreeves Actor Ritu Arya Lila Pitts Actor Justin Cornwell Marcus Actor Britne Oldford Fei Actor Jake Epstein Alphonso Actor Genesis Rodriguez Sloane Actor Cazzie David Jayme Actor Javon "Wanna" Walton Stan Actor Adam Godley Pogo Voice Steve Blackman Executive Producer Jeff King Executive Producer Keith Goldberg Executive Producer Mike Richardson Executive Producer Gerard Way Writer, Executive Producer