There's a listing on Amazon for a set that includes Repugnus and Solus Prime. Repugnus will be a headmaster, and his Titan Master's name is "Dastard".

Link: https://www.amazon.com/dp/B0785P78QD...eibertron07-20

Strange thing about it is that the Prime Master is Solus Prime. Solus Prime already comes single-carded as Octopunch (hence why I treat this as a rumour).