Lambda

Lambda (ラムダ) (Λάμβδα) is a member of Shadow Garden, being one of the Named Numbers ranks which in charge of training new members. She is also one of the earliest recruits in the organization after the Seven Shadows began their expansion after the rescue of Claire Kagenō.

Appearance
Lambda is a Dark Elf with gray hair, sharp golden eyes, beautifully plump lips, with a tall stature and refined muscles from years of military training. She wears a Slime Bodysuit molded into a military uniform, accompanied by an officer's cap and jacket draped on her shoulders, the style of which she is accustomed to having served in the Velgalta Empire's military. At times, she'll have one eye open and routinely analyzes whomever crosses her vision, such as Rose Oriana when she joined Shadow Garden.

Personality
Being that she was formerly a military officer in the Velgalta Empire, Lambda is a strict instructor and harsh towards trainees, given her background and to ensure they're up to whatever tasks soon follow. Such as Rose Oriana, 665, and 664. Whenever someone joins Shadow Garden's ranks, Lambda will not inquire into their past, as all numbers are just that, with who they were originally being knowledge privy to the executive officers, like Alpha, Beta, Gamma, and Epsilon.

Background
Lambda was once part of the military of Velgalta Empire, but after becoming "possessed", she was captured by the cult and was taken to a hidden facility. While a Cult prisoner, the Seven Shadows attacked the facility and found her as the only surviving captive. Epsilon then curing Lambda by healed her and restoring her to her true form. Following this rescue and the revelation of the truth of the Cult of Diablos, she joined Shadow Garden to which she earned her "Named" Rank no. 11 and becoming Named Numbers when she would identify herself as Lambda.

Mist Dragon and Alexandria
When Shadow Garden still had a two digit membership, Lambda was in charge of training the new recruits due to her background in the Velgalta military. But as their small village grew in population, training space became an issue expressed by Lambda and the Seven Shadows. When the Seven Shadows sought a new location for a secret headquarters, Lambda was among the chain of command to relay the situation to Shadow. When her master defeated the Mist Dragon that guarded the ancient capital of Alexandria, Lambda was as ecstatic as the others in Shadow Garden to have more space and living quarters for the membership.

God of War Festival
After the God of War Festival, Alpha brought Rose Oriana to the secret city of Alexandria, the hidden headquarters of Shadow Garden. Ignorant to her true identity, Lambda carried out Alpha's orders to train Rose and renamed her to Number 666, and assigned her to partner with 664 and 665 as a new team. Lambda then carried out her instructing No. 666 as she did with all other members in Shadow Garden.

Powers & Abilities
Like the other Named Numbers in Shadow Garden, Lambda is a master fighter, incorporating her military experience with her training under the Seven Shadows. As such, Lambda oversees training the subordinate Numbers in Alexandria, ensuring they have the training and skills to survive their missions investigating the Cult.

Also, Lambda is familiar with the climate and situation of each country from her knowledge when she was working as an intelligence agent and sometimes consults with Alpha as a military advisor.

Trivia

 * Lambda is the first Named Number in Shadow Garden to be a Dark Elf and the second is Omega.
 * Lambda's first animated debut was in the game, before she debuted in the anime by the season finale, Episode 20.
 * Both the appearances and interactions of Lambda, Kai, and Omega are constructs made for the anime, as none of them have made an official debut in the manga.
 * Lambda is officially a canon character from both Web and Light Novel from the beginning, while Kai and Omega are the Web Novel character before being adapt into the anime.