Lineage. The Technomage Archive, #2

Ennd's Academy is under attack. Ceril Bain is on the run, only a day after waking up from a coma and learning that he lost his arm and leg in battle. Terrorists armed with powerful magic are killing everyone around them, and Ceril's team barely escape with their lives. They go to the only place they think they can get some answers: Ceril's childhood home. While there, an energy storm forms in the garden where Ceril found his Flameblade over six years ago and the team is transported back to Jaronya, the toxic world that almost killed them all three months before. This time, though, Ceril and the others are helped by a friendly angel named Watcher.
Despite this welcomed help, they are captured and imprisoned in the sentient city of Helia. Meanwhile, Ceril's grandfather is having an adventure of his own. After the shocking revelation that Ennd's Academy's new headmaster was working with the home invaders who tried to kill him, Gramps is drawn back into a life he thought he had left behind. Someone who has stolen Gramps' former identity, the legendary demigod known as the Untouchable, and is impersonating him and performing atrocities in his name. As he continues on his quest for answers, Gramps discovers just how much he has changed.
Once a ruthless demigod with the power to create universes, he has worked at learning how to be an ordinary man. He now must decide who he wants to be: the all-powerful Untouchable of legend or the kind-hearted and soft-spoken grandfather of Ceril's childhood.  No matter his choice, his and Ceril's lives will never be the same again.