Yes.
Fire Emblem: Awakening spoilers, but it was bound to come up during the RP anyways. Robin is actually supposed to be the vessel of Grima, the Fell Dragon. The Grima you probably know is the one from Lucina's timeline, that fully possessed Robin and destroyed the world before traveling back in time to stop Lucina from changing things. Due to the fact that at the end of Awakening Robin no longer has the seal of Grima on his right hand, you can guess how that went. I'm not sure what point in the timeline Z pulled Grima from, possibly Grima as he had just appeared in Chrom's time.