The rivals of anyone who's not in this picture has either already been made by me or has already been revealed to be made in the future.
For the curious ones here are the spoiler-free rivalries of the current roster:
Lee Saunderson Vs. Sonny Slaven
Brad Till Vs. Billy Slaven
Matthew Vs. Harry B
Amanda Vs. Oscar
Talking Joe Vs. Maxwell
Pete Vs. Finn Palmer
Captain Underpants Vs. Professor Poopypants
Horrid Henry Vs. Moody Margaret ...smees ti os ro
Action 52 Vs. Thin Air
Tim Carter Vs. Dincent Dan the Science Man!
Angry Boss Vs. BRUUUUUUUCETON!
Harry Hill Vs. Otto Hill (his evil twin!)