When a young Vikings village is destroyed, he must get help from the mysterious warrior only known as 'The Dane Axe' in order to get revenge on those who killed his family.
The Dane Axe
Where screenwriters learn the form and logline their screen ideas.
The Dane Axe
"Seeking revenge, a novice viking hunts down his only hope; the mysterious warrior known only as The Dane Axe."
I think this logline "works" - all the elements are there, I think, but I'm not fully engaged to want to see it. I don't know why, I guess it's that elusive "hook"? Just some feedback, might not be shared by your audience in general.
This is an attempt to shorten your logline without taking anything away:
"After a young viking's village is destroyed, He must enlist the mysterious warrior known as 'The Dane Axe' to avenge his family."
However you also might want to tell us a little bit about who killed the family in the logline
Hope that helped. Good luck with this!