River of Magic

Mysterious flying giants appear in the sky. When they land, they don’t try to communicate. One opens a portal into the afterlife reward and another opens a portal into the afterlife pit. All attempts at understanding them fail, partially due to a ring of protection surrounding the giants. Able to survive inside that ring, a priest feels that the giants have a religious significance of which he holds a part. Then, war breaks out. The modern world is destroyed.
Trying to determine his roll with the giants, the priest finds a home among an army of displaced soldiers. Jealousy and disappointment plague the priest as his companions, who can also survive inside the giant’s radius, develop abilities. Over the years as society begins to rebuild, the priest’s admiration of the giants turns to loathing. They seem to be the source of magic popping up all over the world and people begin referring to them as Gods.
Going to great lengths, the priest attempts to bring back his former religion. He goes so far as to form an army so that he can force people to convert back to what he calls the true religion. Finally in a manic frenzy he uses dark magic and sacrifices himself to create a sword designed to kill the giants. Nothing goes as planned and the sword falls into hands of a young soldier. Battling saber tooth squirrels, evil wizards, and inept superiors, the soldier finds himself on a path leading toward the priest’s ultimate goal.