Cassandra

Cassandra Nerenied is the mastermind behind the Lady’s Village. An amoeba who believes in social darwinism (survival of the fittest), Cassandra is a ruthless and hateful monster, who believes that the world should reject the weak, and devours every human that trespasses into her village. She battled Alice the XV (Fifteenth), who believed in coexistence, for the title of the Monster Lord on equal terms, but lost.

Luka investigates the Lady’s Village having heard of a rumor that men never return once they step in, and during a discussion with Cassandra, she points out there's no truth to it. However, Alice the XVI (Sixteenth) notes something strange within the village; there are no men. When Luka heads back, the females reveal to be monsters and attacks under Cassandra's order. As Luka heads out to defeat the mastermind, Alice wonders if he stands a chance against her

After defeating Emily, Cassandra’s daughter, the mastermind shows up. The sealed scylla begs her mother to restore her before fighting, however, much to Luka's horror, Cassandra devours her, saying that the world revolves around survival of the fittest. Cassandra reveals her true form, along with her house transforming, and attacks.

Luka barely holds out until Alice intervenes and explains about her mother's and Cassandra's backstory. As they talk, Cassandra renders Luka immobile and attacks Alice with her corrosive flesh. As the Monster Lord and an issue from the previous generation, Alice must pass judgment on Cassandra. After realizing the technique of Cassandra, Alice uses her Eyes of Chaos to dissolve the flesh, which also begins dissolving Cassandra. The amoeba begs for mercy, but Alice's eyes go cold, stating that she'd tread Cassandra's ideals for assisting a weak monster. Without Cassandra, the Lady's Village becomes leaderless and empty.

Encyclopedia Entry
''“The Lord of Lady’s Village, she also competed against Alipheese the 15th for the Monster Lord’s throne. Extremely strong, she is one of the most powerful monsters in the world. It appears as though she can trace her lineage far down the line to the Fateburn family.''

''An extremely cold-blooded monster, she preys on any man to come into her village. Her victims are believed to be in the many hundreds.''

''Holding the genes of many different monster lines in her, it seems as though she can produce offspring of many different types. In addition, she is able to control her flesh freely. Using that, she can form her digestive organ outside of her own body, and watch her prey be digested with her own eyes. Wrapping up her prey in her organ, Cassandra usually forces them to have multiple orgasms, until they have no semen left. After that, she enjoys watching them as they slowly dissolve away.”''

Battle Overview
A powerful monster that is almost as powerful as the Four Heavenly Knights, she should not be underestimated. She has various bind attacks and deals high damage, so Gnome is required for this battle.

After dealing some damage, Alice intervenes. Dialogue ensures and Alice forces the flesh to dissolve Cassandra, thus killing her.

If Luka succumbs, a bizarre organ shapes around Luka as its flesh squeezes his penis. If she defeats him with Prey's Requiem, she embraces him as her flesh surrounds him. In either case, she ends up devouring and killing Luka.

Trivia

 * All of her skills are named after different subgenres of music.