Hetalia-Ukraine

Ukraine was anything but a crybaby during the time of Kievan Rus. She was quick-tempered and ruthless towards her enemies. That changed when she and Russia (back then the Duchy of Moscow) were captured by the Golden Horde. During their capture, she took all of the blame on herself and was tortured for several years. That was over a millennium ago, and she is still traumatized by the events that happened back then, this developing into her fidgety personality.