After Opticron restored Cybertron, Arcee went back to Earth with Spike and Daniel Before merging with Optimus and the Matrix, Unicron stored his essence as Angolmoir Energy on Earth It infected and killed Arcee, destroying Earth and creating the even more powerful UNICRONCEE
Opticron Primus In this alternate universe without Rodimus, Optimus Prime used the Matrix Instead of destroying Unicron he merged with him becoming universal planetary savior