RuneWarriors by Tom S. Parker

It's the eve of the Festival of Greatness and Dane has a big problem. He's yet to choose his nickname. Dane the Dangerous? Dane the Despicable? He can't decide. But when Dane sees his proud father shamed by the evil tyrant Thidrek the Terrifying, Dane's indignation earns him a moniker that sticks—Dane the Defiant! And when Thidrek kidnaps Dane's beloved Astrid in hopes of trading her for the ultimate power of the gods, Dane defiantly goes after him like a bat out of Valhalla. Braving treacherous seas, deadly creatures, and a lovestarved Frost Giant, Dane and his rowdy band of Norseboys embark on an epic quest to end Thidrek's reign of terror and take their place among the greatest Viking heroes of all time.