Erubetie

Erubetie is one of the Four Heavenly Knights, she came joint second/third in a battle royale for the title of Monster Lord when she and Tamamo knocked each other out, leaving Granberia and Alice as the final combatants. The Queen of the slimes, Erubetie is embittered over humanity’s pollution of water, drastically reducing the slime population in the process. She is calm and emotionless, and often keeps to herself, as she did not appear in Chapter 1 (having “shut herself” in Undine’s Cave). She is also Undine’s closest friend.

Erubetie is a collective consciousness of multiple women who she has absorbed throughout her life, pulled together by one iron will. Her personality is therefore said by the encyclopedia to be warped by these multiple individuals absorbed. All of those absorbed by Erubetie were female, while all of the males were dissolved into food.

Manipulator of water, she can use her body to create powerful whirlpools. Her most powerful, infamous attack is Melt Storm, which deals a whopping 1,500 damage and can easily defeat Luka in one hit (in both battles, if he does not have the proper guarding tools).

Hateful of humans for their actions, she will kill them without mercy.

Biography
When she meets Luka for the first time, she aims to kill him, but Undine stops her. Erubetie leaves, letting Undine deal with the human.

In the Monster Lord’s Castle, she fights Luka after Alma Elma and Tamamo, and unlike them, she won’t tutor him nor show any mercy.

She talks as they fight; to the slimes, "coexistence" means being driven out of their homes time and again as humans pollute the bodies of water where they live. Luka says they don't realize the harm they're doing, and if only--- but Erubette cuts him off, saying that she'll make humans realize it by turning that same pain and terror back upon them. At the next opportunity, Luka asks her if she's ever appealed to the humans directly - they aren't fools, and many will sympathize if she'll just plead her case. She accuses him of being a hypocrite, coming here in the name of peace with weapons drawn; he fires back that she's no better, playing the victim while leaping to violent solutions rather than using reason. She looked down on humanity from the beginning, never once thinking to approach them on equal footing. Luka knows a human just like her, blinded by his loathing of monsters; by his own admission, that man hated monsters because he feared them, and that meant he could never understand them. Erubette says she's fine with that, even as Luka tries to show her that inflicting greater terror on humans will only push them farther away. She can't forgive what humanity has done to her people. She has to retaliate; Luka vows that if that's the case, he'll always be there standing in her way.

When being backed down, she quickly divides in order to attack from all angles. Unlike Kitsune and her Clone Jutsu, the Erubetie Triplets are connected to each other; when Luka attacks, another one sprouts in its place.

Salamander chimes in and tells Luka that he has to defeat all of them simultaneously. Salamander asks him why he picked up the sword, and replies it was to fix Erubetie's mistakes. Using determination to summon the purgatory flame he is able to defeat the Triplets with Vaporizing Rebellion Sword.

Being defeated by the very thing she despised, Erubetie clings onto Luka and transforms into a nuclear bomb, which can potentially wipe out the continent and all its inhabitants. Luka convinces her to stop as she’s merely throwing both of their lives away, and by trampling on with the lives of other monsters, she’ll be no better than humanity. Realizing her intentions are senseless, she backs down, seeing how pointless their fight is; if they killed each other, no one would benefit anything.

After Ilias announces that the Monster Lord’s Castle will become a "second Remina" and leaves, Erubetie reports that Angels and Chimeras have begun to lay siege on the castle; the monsters have moved in to intercept but it is too much for them.

Erubetie (1)
''“One of the Four Heavenly Knights, she is a slime monster. Called the Queen Slime, she is the most powerful of all the slime monsters. Able to divide and expand her body at will, her attacks are very unpredictable. She also seems to be capable of controlling water at will, using it to inflate her own body. In this way, she can even create a massive tsunami of slime.''

''Hating humans that pollute the water, she rarely appears before them. If any human sets foot in her home, she will show them no mercy. Erubetie will use her body itself to wrap them up and dissolve them inside her slimy body.''

''Not very interested in her duties as one of the Four Heavenly Knights, she rarely involves herself in their troubles. She has a calm personality, and is very fond of her fellow slime brethren. Due to that, her hatred of humans is deep-rooted.”''

Erubetie (2)
"The Queen Slime and one of the Four Heavenly Knights, Erubetie bosts unmatched vitality among monsters. In actuality, she is a colony of over 10,00 slime spirits and other monsters that is controlled by a single will. Most willingly fused with Erubetie, but there are some who were attacked and taken by force. She cannot technically be called a Slime monster any longer. Erubetie keeps control over the colony inside her with her iron will.

''That said, the only ones taken inside her colony are females. Males are apparently incompatible with her, and are instead dissolved and eaten.''

''When facing humans, she is filled with both anger and despair. AT one point, she desired to live with humans in peace... But due to thousands of beings inside her, it may be that her personality has become quite confused."''

First Battle
In the first battle, immediately use Gnome and then Guard, otherwise Luka won’t endure Melt Storm. Wait a turn, and Undine will intervene.

If defeated and overwhelmed by the whirlpool, Erubetie straddles Luka and performs a penetration through her lower body (slimes technically do not have vaginas) as her mucus consumes him. Afterward, he is then killed and dissolved into Erubetie's food.

Second Battle
In the second battle, unlike Alma Elma or Tamamo, she hits two times higher than them. The use of Undine and Serene Demon Sword can help shave off a good amount of her HP before backing down to the Sylph + Gnome + Vaporizing Rebellion Sword combo. However, even with Sylph, there is still a high probability that Luka will not avoid her attacks. Meditation is strongly suggested.

Do not use Salamander in this battle, otherwise the later scripted events will not occur.

She has three attacks that are potentially lethal: Melt Storm, which deals a whopping 1,500 damage (around 800 with Gnome up). Heaven's Prison, which requires attacking for three times to break free, however if she uses Neverland Frontier and Sylph isn't up, it equals a KO. And Divine Destiny, which requires three Struggles otherwise Luka automatically loses.

When her HP is shaved off enough, Erubetie will start dividing into Triplets. Perform a normal attack, and the defeated slime will be replaced. Use Salamander afterwards, whose power will be boosted. Then use Vaporizing Rebellion Sword to eliminate the Triplets.

Erubetie will then grab onto Luka and put him into an unbreakable bind for three turns as she transforms into a bomb. Dialogue ensures, and after that, she will let go, and the battle will be over.

Luka is unable to Surrender nor Request as she will not hesitate to explode.

If Luka succumbs, Erubetie shrinks his body and mind into a child-like state, basically wiping his memory. She divides to prevent him from escaping, and each of them crowds him; one of them holds him down, another french kisses him, and the third gives him a handjob and soon does penetration. Instead of killing him, he is kept as a sex toy.

Trivia

 * Despite the fact that she is a slime, she does not have any healing abilities.
 * According to Alice, due to her status as the Slime Queen, Erubetie can live and survive in any climate.
 * Erubetie is the only Heavenly Knight in the game to not appear in Chapter 1. As well, Erubetie so far has the least appearances out of the Four Heavenly Knights. This can be credited to her anti-social personality.
 * Erubetie is the only Heavenly Knight that does not require an active Spirit in order to inflict damage to her.
 * Erubetie and Luka have multiple exchanges in battle, which is why it is wise not to skip the text between attacks if one wants to follow along with the story. This marks the only time in battle where in-battle exchange occurs without any form of random interference coming from an outside source.
 * According to her second encyclopedia entry, she has a lot in common with Cassandra, both being monsters formed of a maleable substance, being gestalt monsters consisting of whatever they absorb with a core personality and having very nihilistic views on life in a "survival of the fittest" frame of mind.
 * With that in mind, the same entry also states that Erubetie cannot be technically regarded as a slime monster anymore.