The third son of Odin, he is the guardian of justice who grew to full stature in just one day.  
It is unknown whether he survives Ragnarok, but it is known that he avenged the death of Balder by using an arrow to kill Hoder.  The third son of Odin, he is the guardian of justice who grew to full stature in just one day.  FTP, name this Norse deity who slew Fenris-Wolf and is expected to help repeople the earth with his companion Lifthrasir.
It is unknown whether he survives Ragnarok, but it is known that he avenged the death of Balder by using an arrow to kill Hoder.  
Vali or Lif