Queen of Hearts

The Queen of Hearts (ハートの女王 Hāto no joō) is the apparent main villain of Succubus in Wonderland, who is under a curse from the White Rabbit that causes her to become a cruel tyrant. She is the ruler of Wonderland and the mother of Lewis and Carroll.

Background
The Queen of Heart was beloved by her subjects for being a kind and gentle ruler. At some point, she created her two daughters, Lewis and Carroll, out of her own magical power. She was a good mother to them. On Hearts Day, she and her daughters would fly balloons and make wishes to celebrate the occasion. Her own wish was to remain together with her family and to be a respectable queen.

One day, the Queen was cursed by the White Rabbit, causing her to change into a cruel tyrant. She ordered her subjects to be imprisoned and executed for the slightest of offences, and forbade them from flying balloons on Hearts Day. Due to her power, none of her subjects could resist her. At some point, she came up with a plan to execute many of her subjects on Hearts Day, which would increase her power even further.

In response to this change, Lewis ran away, looking for a way to restore her mother to normal. Carroll remained loyal to her mother, who ordered her to bring back her sister for re-education.

Succubus in Wonderland
Eventually, Carroll returns to the Queen of Hearts and reports that she's caught some criminals. The Queen asks about Lewis, causing Carroll to admit that she failed to capture her. The Queen orders her to bring Lewis in the next time, and warns Carroll to remain obedient lest she meet the same fate.

Later, the Queen angrily asks a subordinate about Carroll's whereabouts. The subordinate says that she isn't in the castle. The Queen threatens to throw the subordinate into prison for not reporting this earlier, causing her to run off. Alone, the Queen declares that Carroll will be executed as well for betraying her.

Eventually, Lewis and Carroll return to the castle, along with Reto, a human boy that they're working with. The Queen declares that, as punishment for her daughters' disobedience, she'll return them to magical power and then remake them as obedient slaves. She offers to reduce Carroll's punishment if she betrays the other two. Carroll pretends to accept this offer, but instead hits the Queen with a spell that harms only the evil. Enraged, the Queen summons her soldiers, but the Hatter and Cheshire Cat appear, the former using a treasure to paralyze all the soldiers. Due to experiencing strong emotions, the curse on the Queen temporarily weakens. Groaning, she warns her daughters to flee and then teleports them all away. The trio confront her again and a fight begins. The Queen has incredible power that makes her seemingly invincible, but Carroll and Lewis appeal to her original self, causing her power to gradually fade. She tries to convince Reto to leave as her daughters will inevitably betray and kill him, offering to spare only him if he agrees, but Reto refuses. Finally, the Queen is defeated and Carroll uses her spell again, breaking the curse.

Back to her original personality, the Queen thanks them and says she'll make amends for everything she's done. Lewis asks the Queen to help Reto return to his world, and the Queen gives him a key that, when used with a magical monument on the castle roof, will open a one-way path back home. The three succubi say goodbye to him, though add flirtatiously that he can always come back to them. Reto uses the key and disappears. The Queen then tells her daughters to prepare balloons as they'll make this a Hearts Day that everyone will remember.

The credits roll, showing the succubi celebrating Hearts Day by releasing balloons. The Queen and her family are among them, and they release three balloons from the castle roof.

Strategy
The Queen of Hearts begins the battle with a four-layered buff that increases her stats, allows her to regenerate 3000 Vigor a turn, reduces your stats and quintuples the costs of your skill. For the first few turns, there is no point in attacking her (your attacks will only do 1 damage, which will be undone by her regeneration) and you should focus on defending yourself. On the fifth turn, Carroll will talk to the Queen, removing one of the layers. Lewis does the same on the sixth turn, removing a second layer. On the seventh turn, the Queen gives Reto a choice: you can continue to fight her (removing a third layer) or you can stop (leading to an instant defeat). On the eight turn, both Lewis and Carroll talk, removing the final layer. As these layers of buffs are removed, your skill costs will return to normal, then the Queen's damage resistance will decrease, and finally her regeneration disappears. Only at this point should you begin attacking.

The Queen of Hearts is weak to Pussy attacks, and her Hearts suit makes her vulnerable to Spades succubi (e.g. Carroll).

Trivia

 * The Queen is based on the character of the same name from the novel Alice's Adventures in Wonderland. Both characters are foul-tempered and order people to be executed for the slightest offense, though Succubus in Wonderland's Queen does this because of a curse. Another difference is that the original Queen of Hearts is depicted as ugly in the novel's illustrations (and also in some adaptations), while this version is a beautiful succubus.