Nine's Grandfather was Nine's guardian and lived with him in a small hut in the country as he liked to do things the "old way", without technology and speedcraft. He was described as a burly man with a bushy black beard who dressed roughly with ceremonial necklaces.
In terms of Legacies, he describes his gift that gives him rare glimpses at the threads of destiny. He always knew that Nine was special and important to the Loric race. He knew that the day would come when Sandor would come to collect him, and that something consolidated when he met Sandor for the first time. Nine's grandfather first meets Daxin (Nine's original elected Cêpan), along with Sandor when a large violet beam of light appears near the city (causing alarm as the Elders were away and could not be contacted). Daxin and Sandor were initiating steps towards Pittacus' Evacuation Protocol in case it was a threat.
Two weeks later Sandor travels to his home again in between the first and second waves of Mogadorian attacks, in order to retrieve Number Nine and get him evacuated. Nine and his grandfather are in the woods with a campfire, enjoying the festivities of the Quartermoon together with their Chimæra. He shows sadness, telling Sandor that he is all he has - suggesting the rest of his family have died. He also foreshadows that Nine and Sandor will be very important but that Sandor will die.
Nine's Grandfather would have died with the rest of the Loric.