Njala and Alajn watch a badly outnumbered Tuskeri band because Valkyries judge more than who wins. Arni appears to be sprinting toward the honoured death his culture celebrates, yet his grin repeatedly signals a different intention. He sees battle as timing, leverage and nerve rather than a straight exchange of strength.
Earlier feats explain the bone lodged in his brow. Facing a troll in a headbutting contest, Arni continues long after a reasonable fighter would stop. When the frightened troll cheats with a tusk, the blow breaks the weapon and leaves its base embedded in Arni's forehead. The injury becomes a title because he converts what should have ended him into the final move of his victory.
Njala gradually stops waiting to escort him to Starnheim and starts wanting his story to continue. That reversal exposes the strange limit of glorious death: a perfect ending can erase all the unwritten deeds that survival permits. Arni's courage lies partly in fighting, but mostly in refusing the conclusion everyone else has prepared for him.