A mythological fox who accompanies and protects Arieta. He has lived a long time and is the only one of his kind in existence. Sereb was born in the new world after the fox tribe migrated to it through the the space-time fusion plan. Because of his lineage, he has learned to communicate in human tongue if he so chooses.
Two hundred years ago, he was captured by Growsians and subjected to experiments. Arieta rescued him and from then on he stayed by her side. He is very protective of her, and will not allow any harm to come to her. Even after she was put in a cold sleep, he lived to protect the device she was in.
He knew all about Arieta's situation with Gevas and informed Wein. He requested Wein to kill Arieta while vulnerable before the fusion of Arieta and Gevas's souls was complete. If she remained alive, Gevas would be reborn.
When Wein's party came to fight Gevas at the Dimensional Fusion Control Tower, he found a way to save Arieta by using the neural device. Sereb offered to attach the device to Gevas. He was weakened from the time spent inside the magic circle, and stayed behind to rest after the party rescued Arieta and defeated Gevas.
If Arieta is not saved, she will die and Sereb will join Wein's party.