"Mord" means murder in Scandinavian languages. In the late viking age, it was not an uncommon name.
Magnus says: "without law the land will be laid to waste". This is a variation of the proverb "Land shall be built by law but by lawlessness be wrecked" which cited in several old law codes from Iceland, Denmark, Sweden and Norway. It's famously cited in Njáls saga, which serves as the primary inspiration for the Viking Saga. The first part of the phrase was also the motto of king Charles XV of Sweden and is the official motto of the Icelandic police force. It is quoted in marble above the entrance to the old City Court in central Copenhagen.