Nega-Shantae

Nega-Shantae is an evil clone of Shantae created from her own genie magic. She is the final boss of Shantae: Risky's Revenge, in which she appears as a colour swap of Shantae. Nega-Shantae also makes a brief appearance in Shantae: Half-Genie Hero when Shantae's magic is converted to dark magic.

Shantae: Risky's Revenge
In the climax of the game's plot, Shantae is forced to surrender the three Magic Seals to Risky Boots so that she can restore and use the Magic Lamp's power. Once the lamp's power is restored, Risky uses the lamp to enslave Shantae; although since Shantae is a half-genie, The Magic lamp only captures her genie half, leaving Shantae as a pure human. With Shantae's other half trapped inside the lamp, Risky commands it to destroy Shantae, resulting in the birth of Nega-Shantae which does her bidding.

After a long battle, Nega-Shantae is defeated and explodes, thus resulting in Shantae's genie half being completely destroyed, and Shantae being left as a pure human. Shantae is left stunned by this loss.

Risky taunts Shantae over how she's now a powerless human and escapes.

Shantae: Half-Genie Hero
Near the climax of the game's plot, Shantae has successfully helped Uncle Mimic create the Dynamo by fetching the last needed item, the Zombie Hamster. Briefly upon running the Dynamo the machine bursts into a cloud of black smoke and blasts Shantae with a black bolt of energy, immobilizing her. Risky Bootsenters the scene and reveals that she has swapped Uncle Mimic's blueprints so as to build the Dynamo to Risky's specifications. She explains that the machine was built to generate great quantities of electricity with a significant counterflow of negative energy as the machine rotates. Her altered plans have converted the negative energy into dark magic which transforms Shantae into Nega-Shantae. After Risky leaves with the Dynamo Nega-Shantae threatens to attack her friends and asks them to beg for their lives. The screen fades to black and enters Shantae's sub-conscience, Shantae pleads with Nega-Shantae to stop her actions but is ignored and is told by Nega-Shantae that she will remain in her sub-conscience where Shantae will have no control over her actions. Shantae's friends attempt to reach Shantae to tell her to fight the Dark Magic and remind Shantae of her defining character traits. Sky reminds Shantae of her loyalty and honesty, Rottytops reminds Shantae of her kindness and compassion, and Bolo reminds Shantae of her Strength and courage. Shantae is then able to regain her consciousness and the dark magic dissipates from her body.

Powers and Abilities
Nega-Shantae has all of Shantae's transformation abilities, but uses them in ways that Shantae herself can't even match. In Risky's Revenge, Nega-Shantae can transform into a Monkey and attack Shantae with repeated Monkey Bullets, use the Elephant form to jump and stomp on Shantae's head, or become a Mermaid and bombard Shantae with a shower of Mermaid Bubbles.

When Nega-Shantae is damaged 200 times she will do the stage clear animation and charge up power, causing her attacks to become twice as dangerous as she speeds up her dancing, uses the Monkey Bullet faster, stomps down more times with the Elephant Stomp and her Mermaid Bubble attack becomes faster and lasts longer.

Nega-Shantae is defeated when she is damaged 200 times.

Trivia

 * Nega-Shantae's name is not actually revealed during the course of Risky's Revenge, but rather in the promotional material for Half-Genie Hero. In the Achievements for the Director's Cut of Risky's Revenge, the character is simply referred to as "the genie clone".
 * In the Shantae: Half-Genie Hero Kickstarter game, one of the stretch goals is a new gameplay chapter titled A Dish Served Cold, in which Nega-Shantae returns as an enemy. Since the campaign received roughly $950,000[1] ($50,000 away from the "A Dish Served Cold!" Stretch goal), Nega-Shantae only makes a cameo in Shantae: Half-Genie Hero with no additional transformation, chapter, or boss battle. However, she is the main antagonist of the "Friends to the End!" DLC quest.
 * Nega-Shantae's Eye-Color has been green in Risky's Revenge while in Shantae: Half-Genie Hero her eye-color was both yellow and red (Yellow in her character portrait and Red for her in-game sprite) the reasoning behind these varying eye-colors is currently unknown.