So, I was thinking some day earlier how the show is giving everyone an arch-enemy to fight against. Optimus has Megatron [obviously]. Bulkhead has Breakdown. Arcee has Airachinid. This leaves us with Ratchet and Bumblebee without enemies [Wheeljack as well, but he was only a very brief character]. Who would you like to be Ratchet/Bee's arch enemies?