Eins

"The sharing of knowledge is this world's living will."

- Eins, Volume 2 Appendix

Eins (also spelled Einz and Ains), also known as Sage Eins (or Teacher Ains), is the guild master of Honesty. He is a Human Kannagi-Scholar and a member of the Round Table Alliance.

Personality
Eins is a generous individual, founding his guild to help people by releasing tactics and guides to defeating raid bosses. It is this generosity that gains him the animosity from other raiding guilds, however, and is his fatal weakness. His inability to turn people away places an immense burden his guild as members of D.D.D abandon it in favor of Honesty after Krusty's disappearance, and it creates a rift within his guild that he is too weak-willed to mend.

As time passes after the Catastrophe, Eins is the one most attuned to those who are discontent with this new world and wish to return to the real world. He attempts to improve life for those types of individuals, but his suggestions are shot down by the rest of the Round Table, filling him with a sense of helplessness.

It is possible that Eins is serving as a double agent for Plant Hwyaden under the alias of "Agent One." If he is indeed Agent One, then it is likely that he was motivated to turn on the Round Table due to Nureha's claim that they had found a way to return home.

The Catastrophe
After being trapped in the MMORPG Elder Tale, the Adventurers discover that the Intercity Transport Gates are not working, making it difficult to travel to other towns. Eins, alongside many other players, is distressed by this news.

Return of the Goblin King arc
Eins makes a brief appearance during the post-expedition party at the Ancient Palace of Eternal Ice with Roderick.

Route 43 arc
Shiroe becomes worried that he can't stop Eins from doing a certain, undisclosed something with the research conducted on the Fairy Ring.

Homesteading the Noosphere arc
Eins becomes increasingly agitated by the slow progress at finding a way to return home. In particular, his guild is coming under greater and greater strain: without Krusty, many of D.D.D's members were leaving, with a great number of those people instead flocking to Honesty. However, those members were also unwilling to work for themselves and simply leeched off the other original members of the guild, building resentment within the guild. While Eins was unwilling to kick out any members and leave them to fend for themselves, he also couldn't sustain all of them. He found little support within the Round Table, as his suggestions were found to be too selfish and detrimental to the city as a whole.

When the server is attacked by the Eternal Moths, Eins uses this situation to push the Round Table towards focusing more on returning home than making life in Theldesia comfortable, something that Shiroe viewed to be an omen. In the anime, before the Shibuya Raid Team departed for Calling Fortress, Shiroe tells Eins that "For now, [he would] think of [Eins] as a member of the Round Table," a reference to Eins' possible status as Plant Hwyaden's spy, Agent One.

Log Horizon: West Wind Brigade
Eins and William Massachusetts are briefly seen among those purchasing Crescent Burgers. At the start of the Round Table Conference, he and Krusty appear at the entrance of the Guild Meeting Hall, where William, Isaac, and Soujiro Seta had already arrived. They then enter and take their seats, finding the other guild masters invited already seated.