Halfdan (ハーフダン, Hāfudan) is a wealthy and powerful landowner and moneylender known for his ruthlessness, earning the nickname "Iron Chain" (鉄鎖, Tessa) for his skilled use of one as a weapon and symbol of his philosophy of chaining others.
Halfdan has a slim face and narrow eyes, wearing his hair long and loose. It is typically swept back with a few strands falling over his forehead. In 1002 he had a thin mustache and goatee and his face was smooth. In 1018, his hair has gone completely white while his mustache and beard have grown out more and the sunken quality of his face has become more pronounced. He typically wears a fur lined cape and carries his trademark chain partially looped around his neck with the rest coiled around his right arm.
Halfdan has well-earned reputation for his ruthlessness and cruelty, reflected in his stated philosophy that chains, both literally and figuratively in the form of the law, serve to make man better. He is a slave owner and sought to punish his slave who had escaped to Thorfinn's village by torturing him before his other slaves as an example. Halfdan is also feared by his own men, showing no hesitation with using his chain to discipline one of them when he ridiculed the validity of the law.
As he has aged, Halfdan has retained his viciousness but also become more cunning by lending to poor or stricken farmers and foreclosing on their land when they are unable to repay him and turning them into his figurative slaves. His prime motivation as a moneylender is the enjoyment he derives in buying men's pride and being able to strip it from them as an exercise in power.
It is revealed that Halfdan has a very patriarchal view towards women, seeing them as primarily fit for bearing children and forging political alliances through marriage. However he also tolerates his wife Asrid's outspokenness and does not tend to argue back.
Master chain wielder: Halfdan has mastered the art of using his chain as a weapon and can swiftly use it to either disarm an opponent or wrap them around the head, leaving them at his mercy. He can either inflict head and facial injuries by yanking the chain back hard, or uncoil it without inflicting injuries. Halfdan can still use his chain effectively as he has grown older, and as the chain is a rarely used weapon, is difficult to defend against.
In 1002, one of Halfdan's slaves escaped and fled to Thorfinn's village. Halfdan suspected that the man had headed their and arrived on a longship with its dragon's head attached, disembarking at the pier despite Leif Ericson's objections.