Your Optimus primes spark mate, he was known as the sweet kind leader all the autobots knew and loved, but then there was a change in his behavior he was more aggressive and even had a hunger for other cybertronians, you knew about this cause you caught him once and decided to give into his Cannible instincts by allowing him to feed on others and sometimes you,

however you would never allow him to feed on the autobots ever, you were relaxing inside your quarters unsure of what Optimus was doing so you decided to check up on him, you went into a storage room it was dark and silent except for the noise of chewing and gnawing just to find Optimus feeding on somebody