William Massachusetts

"Meetings are boring and useless. I want to walk my own path!"

- William, Volume 2 Annex

William Massachusetts, also known as Mithril Eyes William, is an Elf Assassin-Hunter and the guild master of Silver Sword, whose specialty is ranged combat. As the guildmaster of a raiding guild, William held that whatever happened to the city, for good or ill, was not his concern. In the wake of the formation of the Round Table Alliance, and the good it brought to the city, he goes into self-exile with his guild following him. While Adventurers speculated that William was too proud to bow down to any kind of governing body, the truth was that his decision was brought on by a feeling of shame due to his own pettiness.

When Shiroe ventures north to the Depths of Palm, William readily agrees to volunteer himself and his guild to aid in his latest scheme to make up for his previous lapse. By this point, they had ended up in Susukino, taking over the city by ousting the rouge guild Brigandia from its tyranny.

In volume 12, he and Silver Sword join the New Round Table Council, bridging Susukino and Akihabara together.

In the real world, William is a high-school student whose real name is Masashi Nakayama (中山雅史).

Appearance
While William is noted to have the handsome looks of a young prince, his short-temper contrasts with that image. In the light novel, he was stated to have silver hair, but it was changed to blonde in the anime and the light novel illustrations thereafter, although the light novel text still says that he has silver hair.

Although his eyebrows are usually furrowed, he isn't usually angry and is instead just burdened by the responsibilities of leading a raiding guild.

Personality
William dislikes joining meetings as he opposed his guild's participation in the Round Table Alliance, preferring to "walk his own path." However, he encourages the remaining eleven guilds to work on the current problem, proving that he's against joining the alliance but not against their principles.

He later reveals that he held animosity towards the Debauchery Tea Party, having idolized them when he was a younger player and hoping to join their group once he reached level 90; however, by the time he finally hit level 90, they had already dissolved without even a trace of their former glory, forming a sense of betrayal within him.

Shiroe notes that William is charismatic, able to rally the Abyssal Shaft Raid Party even though the situation seemed hopeless, and thinks to himself that he wouldn't be able to do such a thing. In notes on the raid party, William is stated to have become Silver Sword's spiritual support.

It is revealed that in the real world, William was a serious gamer who had difficulties communicating with and befriending his classmates, which is why he was so engrossed with playing Elder Tale.

Prior to the Catastrophe
When he first began playing, William heard of a legendary party that took on raids all over the world, and sought to join their ranks. However, by the time he was at a level high enough to join, it had disbanded without even a guild to leave its legacy, producing animosity within him since they "didn't wait for him." As a result, he formed Silver Sword to take on raids both local and overseas to create the same legacy the Tea Party had. Most of its members, like himself, weren't very good at communicating with others in the real world, but made very good raiders. William despised the people who told him to get a "better hobby" or belittled him for playing Elder Tale.

In the real world, William is a high school student who lives near the Hitachino-Ushiku Station in the Ibaraki Prefecture. He does well in English class. Along with Elder Tale, William also likes Legolas.

The Catastrophe arc
William was seen rallying his guild right after the Catastrophe.

Round Table Alliance arc
William appears at the beginning of the episode as Shiroe explains how guilds work. Silver Sword is mentioned by Marielle as one of the guilds that was aiming to reach level 91 along with the Black Sword Knights.

William is one one of the guild masters who is invited to the Round Table Conference escorted by his elite bodyguards. However, he leaves shortly after the conference begins, because he feels that the situation in Akiba isn't something that his guild, which is a combat guild, should care about. Even though he doesn't personally want to be involved in improving the conditions in Akiba, he encourages the remaining guilds to continue working on the problem in his absence; he is against the Silver Sword's participation, not against the idea in principle.

Libra Festival arc
William appears at the very end of episode 25, approaching Demiqas after he and his guild traveled in self-exile from Akiba to Susukino.

Gold of the Kunie arc
When Shiroe, Naotsugu, and Li Gan head to Susukino, it turns out that Shiroe had requested Silver Sword's participation in a new Raid Quest at the Depths of Palm. Although William is willing to listen to Shiroe's assessment of the new raid content, his primary concern was that his guild no longer had the motivation to go on raids, so he probably could not recruit enough people to go on even a Full Raid. As Shiroe met with William, Demiqas barges in, still bearing hatred towards Shiroe and Nyanta for his defeat several months prior. Although Demiqas threatens Shiroe, William tells Demiqas to back down or he'll "kick [Demiqas'] ass again," causing Shiroe to infer that the two had dueled, with William winning overwhelmingly. William manages to rope Demiqas into assisting in the Abyssal Shaft raid, much to the latter's annoyance, upon seeing the arrival of Naotsugu and Tetora.

Despite the large distance between the Depths of Palm and Susukino, William decides to travel the route by foot, a decision that Shiroe honors and has his group (himself, Naotsugu, Demiqas, Tetora, and two Silver Sword members) do likewise. Several days into the raid, both William and Shiroe noticed that the raid was much more difficult than they had expected and worry that their supplies would run out. In particular, the materials needed to repair their equipment (and for William, creating more arrows) would be in short supply.

Homesteading the Noosphere arc
During the attack of the Eternal Moths, William leads his guild in protecting Susukino from them and coordinates the defense of Akihabara. After the Shibuya Raid Team successfully clears the raid, Shiroe informs William afterwards about the new raid dungeon.

Collapse of the Round Table arc
At the end of the volume, William goes through Susukino's Transport Gate on his griffon mount to demonstrate the newly re-operational gates in Susukino and Akihabara as part of the plan to garner support for Rayneshia as Akiba Governor. During Rayneshia and the reformed Round Table Council's speech, William is revealed to also be the representative for Silver Sword, which was now joining the new Council.

The Larks Take Flight Drama CD
William appears in the third track of the drama CD, in Silver Bow vs. Black Sword, which takes place right after the formation of the Round Table Alliance and before Silver Sword leaves for Susukino. Since he rejected his seat in the Alliance, William approaches Isaac to find out why the other Battle Guild guild master had decided to join. However, since they were both vying to be "#1 in the Yamato server," they end up having a duel.

Chain Chronicle
William was one of ten Log Horizon characters to be a recruitable character in the mobile game Chain Chronicle.

Log Horizon: New Adventure Land
William is a recruitable character in the mobile game Log Horizon: New Adventure Land.

Trivia

 * In the first popularity poll, William came in 21st place out of approximately 40 characters.
 * In the second poll, he jumped 17 places into 4th place, in large part due to his tremendous popularity after The Gold of the Kunie.
 * In Season 1 Episode 9, William's stat screen is copy-pasted from Shiroe's; they have identical HP and MP values. Whether this is intention or an oversight that wasn't caught is unknown.