The Sage Chronicles: Family Matters Book 1

A secret war to save two worlds has been waged for generations - over and over, again. The three principle combatants - the Black Elf known as Sage and his adversaries, the demigods Simon and the Unicorn - have their own reasons for saving the worlds. No matter how many times they've waged the war, and which side won, the worlds died, anyway. Each time, Sage returned to the past to correct the mistakes he made, making sure to obey the laws of time and space, even magic, to save the two worlds. This time, Sage is breaking all the laws, as well as enlisting allies he never imagined having in his previous attempts. So have Simon and the Unicorn. All three know this is their last chance, and they will stop at nothing to succeed.