Small interesting fact, the common word that is used for sword in these novels is 검. Meanwhile, the word used for the Hyeonu's weapon is 도. They both typically mean sword so I’ve been using the term generally. However, after some googling, I’ve found that 도 is more typically used for single-edged swords (also can be known as a dao) while 검 is for double-edged swords. 

Hyeonu's main weapon is a single-edged sword/dao. Since there are future instances where his weapon is changed from sword to a dao, I will be making things clearer by changing all instances of Hyeonu's weapon and his sword energy to dao and dao energy. People other than Hyeonu generally use the common 검 character and it will be kept as sword.