Michael James Arthur Tolan is an ordinary guy. He would be less ordinary if his mind wasn't wiped after a devastating battle that nearly destroyed humanity. But it was, so he is, or rather was, ordinary. He has one dog, a female alsatian called Xena, who he has had since he was a child, and can't remember for the life of him why the dog is called Xena. He lives alone in a huge house in London, and is a Mathematics teacher at a secondary school.
He was killed by Ender when Silas un-wiped his mind at the age of 34. Ender strolled into his hues one day and broke all of his fingers, then fired a laser through his heart because he was having a bad day and needed to take it out on someone.
Tolan was brought back to life a few hundred years later by Silas to help StarGate find his father, Gerald, who held many secrets. When he had to go back to The Land of the Dead, he brought his father with him, as he was dead in the reality that he was needed in. Xena the dog went to live with her half-human counterpart, being an immortal dog.