Seems pretty much a philosophic saying, He swept away down distant paths, Hence, he walked throughout the world trying to find answers for his life, for the world, lying the whole time alone in darkness. He traveled across land and thoughts to find his way. It is a very poetic phrase. Deserves to be emphasized.

Hopefully, this verse is about the raids and the Viking way of living.
Taking you as a Viking history adept I assume you can figure out what weather wild, blackened blade, angry eyes and ruthless raid means. If not I am going to explain.
The Vikings used to travel long distances with their Long Ships, in such trips were common to occur tempests and heavy rains so Weather wild means enduring a heavy tempest or gale. Gotcha?
Blackened blade I think means something spiritual, like my blade is filled with darkness and eagerness, the will of the gods. Yet I am not sure about it.
Angry Eyes, well pretty literal. I think it means the shown facial aspect when the Vikings managed to reach their victims.
Ruthless Raid, Also pretty literal means a pitiless, a Merciless attack. Meaning no mercy for the deviants (Christians or anyone else they attacked)

Perhaps referring to the Christianity, namely, by their point of view the deviated opinion of the Christians about nature, beliefs and so on.
Wayward is like a wrong way, a divergent way. And these strangers in my conception are the new coming culture and their deviated way of living and badly done forays. Trying to change the nordic way of living.